How ___________ beef does she want? - Half a kilo of beef.

Khi nói về một hệ dao động cưỡng bức ở giai đoạn ổn định, phát biểu nào dưới đây là sai?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:

For more than six million American children, coming home after school means coming back to an empty house. Some deal with the situation by watching TV. Some may hide. But all of them have something in common. They spend part of each day alone. They are called “latchkey children”. They are children who look after themselves while their parents work. And their bad condition has become a subject of concern. Lynette Long was one principal of an elementary school. She said, “We had a school rule against wearing jewelry. A lot of kids had chains around their necks with keys attached. I was constantly telling them to put the keys inside shirts. There were so many keys, it never came to my mind what they meant. Slowly, she learned that they were house keys. She and her husband began talking to the children who had keys. They learned of the effect working couples and single parents were having on their children. Fear was the biggest problem faced by children at home alone. One in three latchkey children the Longs talked to reported being frightened. Many had nightmares and were worried about their own safety. The most common way latchkey children deal with their fears is by hiding. They made hide in a shower stall, under a bed or in a closet. The second is TV. They often turn the volume up. It’s hard to get statistics on latchkey children, the Longs have learned. Most parents are slow to admit that they leave their children alone.

Question 25: Lynette Long learned of latchkey children’s problems by _________         

Dao động cưỡng bức có tần số:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:

For more than six million American children, coming home after school means coming back to an empty house. Some deal with the situation by watching TV. Some may hide. But all of them have something in common. They spend part of each day alone. They are called “latchkey children”. They are children who look after themselves while their parents work. And their bad condition has become a subject of concern. Lynette Long was one principal of an elementary school. She said, “We had a school rule against wearing jewelry. A lot of kids had chains around their necks with keys attached. I was constantly telling them to put the keys inside shirts. There were so many keys, it never came to my mind what they meant. Slowly, she learned that they were house keys. She and her husband began talking to the children who had keys. They learned of the effect working couples and single parents were having on their children. Fear was the biggest problem faced by children at home alone. One in three latchkey children the Longs talked to reported being frightened. Many had nightmares and were worried about their own safety. The most common way latchkey children deal with their fears is by hiding. They made hide in a shower stall, under a bed or in a closet. The second is TV. They often turn the volume up. It’s hard to get statistics on latchkey children, the Longs have learned. Most parents are slow to admit that they leave their children alone.

Question 24: “Latchkey children” in the passage means children who ___________         

Nhận xét nào sau đây sai khi nói về dao động cơ tắt dần?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:

In my experience, freshmen today are different from those I knew when I started as a counselor and professor 25 years ago. College has always been demanding both academically and socially. But students now are less mature and often not ready for the responsibility of being in college. It is really too easy to point the finger at parents who protect their children from life’s obstacles. Parents, who handle every difficulty and every other responsibility for their children from writing admission essays to picking college courses, certainly may contribute to their children's lack of coping strategies. But we can look even more broadly to the social trends of today. How many people do you know who are on medication to prevent anxiety or depression? The number of students who arrive at college already medicated for unwanted emotions has increased dramatically in the past 10 years. We, as a society, don't want to “feel” anything unpleasant and we certainly don't want our children to “suffer”. The resulting problem is that by not experiencing negative emotions, one does not learn the necessary skills to tolerate and negotiate adversity. As a psychologist, I am well aware of the fact that some individuals suffer from depression and anxiety and can benefit from treatment, but I question the growing number of medicated adolescents today. Our world is more stressful in general because of the current economic and political realities, but I don’t believe that the college experience itself is more intense today than that of the past 10 years. What I do think is that many students are often not prepared to be young “adults” with all the responsibilities of life. What does this, mean for college faculty and staff? We are required to assist in the basic parenting of these students - the student who complains that her professor didn't remind her of the due date for an assignment that was dearly listed on the syllabus and the student who cheats on an assignment in spite of careful instructions about plagiarism. As college professors, we have to explain what it means to be an independent college student before we can even begin to teach. As parents and teachers we should expect young people to meet challenges. To encourage them in this direction, we have to step back and let them fail and pick themselves up and move forward. This approach needs to begin at an early age so that college can actually be a passage to independent adulthood.

Question 42: According to the writer, failure in life and less support from parents will _______.  

Nguyên nhân gây ra dao động tắt dần của con lắc đơn trong không khí là do ?          

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:

In my experience, freshmen today are different from those I knew when I started as a counselor and professor 25 years ago. College has always been demanding both academically and socially. But students now are less mature and often not ready for the responsibility of being in college. It is really too easy to point the finger at parents who protect their children from life’s obstacles. Parents, who handle every difficulty and every other responsibility for their children from writing admission essays to picking college courses, certainly may contribute to their children's lack of coping strategies. But we can look even more broadly to the social trends of today. How many people do you know who are on medication to prevent anxiety or depression? The number of students who arrive at college already medicated for unwanted emotions has increased dramatically in the past 10 years. We, as a society, don't want to “feel” anything unpleasant and we certainly don't want our children to “suffer”. The resulting problem is that by not experiencing negative emotions, one does not learn the necessary skills to tolerate and negotiate adversity. As a psychologist, I am well aware of the fact that some individuals suffer from depression and anxiety and can benefit from treatment, but I question the growing number of medicated adolescents today. Our world is more stressful in general because of the current economic and political realities, but I don’t believe that the college experience itself is more intense today than that of the past 10 years. What I do think is that many students are often not prepared to be young “adults” with all the responsibilities of life. What does this, mean for college faculty and staff? We are required to assist in the basic parenting of these students - the student who complains that her professor didn't remind her of the due date for an assignment that was dearly listed on the syllabus and the student who cheats on an assignment in spite of careful instructions about plagiarism. As college professors, we have to explain what it means to be an independent college student before we can even begin to teach. As parents and teachers we should expect young people to meet challenges. To encourage them in this direction, we have to step back and let them fail and pick themselves up and move forward. This approach needs to begin at an early age so that college can actually be a passage to independent adulthood.

Question 43: What is probably the writer's attitude in the passage?         

Phát biểu nào sau đây về dao động cưỡng bức là đúng?  

Một con lắc lò xo gồm vật có khối lượng 500g gắn với lò xo nhẹ có độ cứng 50N/m. Người ta lần lượt cưỡng bức con lắc dao động bằng các ngoại lực , , , . Ngoại lực làm con lắc dao động với biên độ lớn nhất là: