Choose the correct sentence which is built from the words and phrases given:

The tenth graders / help / decorate the stage / the eleventh graders / be in charge of / distribute tickets / the twelfth graders / keep public security

Nghiên cứu một dung dịch chứa chất tan X trong lọ không dán nhãn và thu được kết quả sau: X đều có phản ứng với cả 3 dung dịch : NaHSO4, Na2CO3 và AgNO3. X không phản ứng với cả 3 dung dịch : NaOH, Ba(NO3)2, HNO3. Vậy dung dịch X là dung dịch nào sau đây?         

Read the following passage and choose the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (26) __________ for school? According to a new report, today’s generation of children are in danger of getting so (27)________ sleep that they are putting their mental and physical health at (28)_________. Adults can easily survive on seven to eight hours sleep a night, (29)____________teenagers require nine or ten hours. According to medical experts, one in five youngsters (30)___________ anything between two and five hours sleep a night less than their parents did at their age.

Question 27:

Cho 26,9 gam hỗn hợp gồm Mg, Zn và Fe vào 400ml dung dịch Cu(NO3)2 0,75M và AgNO3 1,25M. Kết thúc phản ứng thu được dung dịch X và chất rắn Y gồm 2 kim loại. Cho NaOH dư vào dung dịch X, lọc lấy kết tủa nung ngoài không khí đến khối lượng không đổi thu 30,0 gam hỗn hợp gồm 2 oxit. Phần trăm số mol của Zn trong hỗn hợp ban đầu là.         

Read the following passage and choose the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (26) __________ for school? According to a new report, today’s generation of children are in danger of getting so (27)________ sleep that they are putting their mental and physical health at (28)_________. Adults can easily survive on seven to eight hours sleep a night, (29)____________teenagers require nine or ten hours. According to medical experts, one in five youngsters (30)___________ anything between two and five hours sleep a night less than their parents did at their age.

Question 26:

Cho hỗn hợp X gồm 0,12 mol CuO; 0,1 mol Mg và 0,05 mol Al2O3 tan hoàn toàn trong dung dịch chứa đồng thời 0,15 mol H2SO4 (loãng) và 0,55 mol HCl, thu được dung dịch Y và khí H2. Nhỏ từ từ dung dịch hỗn hợp Ba(OH)2 0,1M và NaOH 0,6M vào Y đến khi thu được khối lượng kết tủa lớn nhất, lọc kết tủa đem nung đến khối lượng không đổi, thu được m gam chất rắn khan. Giá trị của m gần nhất với giá trị nào sau đây?         

Read the following passage and choose the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (26) __________ for school? According to a new report, today’s generation of children are in danger of getting so (27)________ sleep that they are putting their mental and physical health at (28)_________. Adults can easily survive on seven to eight hours sleep a night, (29)____________teenagers require nine or ten hours. According to medical experts, one in five youngsters (30)___________ anything between two and five hours sleep a night less than their parents did at their age.

Question 29:

Cho dãy các kim loại: Fe, Cu, Mg, Ag, Al, Na, Ba. Số kim loại trong dãy phản ứng được với dung dịch HCl là  

Read the following passage and choose the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (26) __________ for school? According to a new report, today’s generation of children are in danger of getting so (27)________ sleep that they are putting their mental and physical health at (28)_________. Adults can easily survive on seven to eight hours sleep a night, (29)____________teenagers require nine or ten hours. According to medical experts, one in five youngsters (30)___________ anything between two and five hours sleep a night less than their parents did at their age.

Question 28:

Kim loại nào sau đây không phản ứng với dung dịch CuSO4?         

Read the following passage and choose the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Why is it that many teenagers have the energy to play computer games until late at night but can’t find the energy to get out of bed (26) __________ for school? According to a new report, today’s generation of children are in danger of getting so (27)________ sleep that they are putting their mental and physical health at (28)_________. Adults can easily survive on seven to eight hours sleep a night, (29)____________teenagers require nine or ten hours. According to medical experts, one in five youngsters (30)___________ anything between two and five hours sleep a night less than their parents did at their age.

Question 30:  

ư