Trong không gian với hệ trục toạ độ $Oxyz$ , mặt cầu $\left(S\right)\text{}:{\left(x+2\right)}^2+{\left(y-1\right)}^2+z^2=4$ có tâm $I$ và bán kính $R$ lần lượt là

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Choose the word that has the underlined part pronounced differently from the rest:  

  found                    count                      bound                        cousin

• Choose the word that has the underlined part pronounced differently from the rest:  

  language                  any                  fancy                   romance

• Choose a word that has different stress pattern:

  History                      English                   Mathematics                       Physics

• Choose a word that has different stress pattern:

  biology                chemistry                     geography                       technology

• Choose a word that has different stress pattern:

  children                      enjoy                        above                       create

• Find a mistake in the four underlined parts of the sentence and correct it:

  We have to cancel the meeting because the chairman's absence.

• Find a mistake in the four underlined parts of the sentence and correct it:

  It's time you begin to study seriously.

• Choose one sentence that has the same meaning to the root one:

  Picking flowers is not permitted here.
  
  

• Read the following passage and choose the best answer for each blank:

           Like any other universities, the Open University can give you a degree. However, you don't have to (1)__________ working to study. It can also open up a whole variety (2)____________ interest. If you have (3)__________ studied before, you will enjoy the special, new pleasure of (4)_______ your knowledge. You will make friends of (5) _____ kinds. You may also (6)______ that your qualification provides new career opportunities.
           You don't actually (7)__________ to the Open University for lectures, but study at home, using television, radio and computer software. You can (8)__________ one class a month if you wish at an Open University centre. Of course, there are exams to take, as in (9)_________ university. If yo u (10)_____________ like to know more, all you have to do is complete the form below. It could be the start of a wonderful new period in your life.

   

  1. A. stop                        B. end                          C. break                         D. leave
  2. A. from                        B. of                             C. in                               D. for
  3. A. ever                        B. never                       C. often                          D. always
  4. A. growing                  B. changing                  C. adding                        D. increasing
  5. A. all                           B.each                          C. both                           D. every
  6. A. suggest                  B. find                          C. wish                           D. want
  7. A. join                         B. enter                       C. arrive                          D. go
  8. A. give                        B. attend                     C. learn                           D. study
  9. A. any                         B. some                       C. many                          D. most
  10. A. did                        B. will                           C. would                         D. can

   

• Choose the word that has the underlined part pronounced differently from the rest: 

  contain                  said                       pail                 paid