Trong không gian với hệ tọa độ Oxyz, cho mặt phẳng P : x − 4 y + 3 z − 2 = 0.  Một vecto pháp tuyến của mặt phẳng (P) là:

A.  n 1 → = 0 ; − 4 ; 3 .

B.  n 2 → = 1 ; 4 ; 3 .

C.  n 3 → = − 1 ; 4 ; − 3 .

D.  n 4 → = − 4 ; 3 ; − 2 .

Trong không gian Oxyz, cho 2 điểm A(2;-1;2), B(0;1;0). Phương trình mặt cầu đường kính AB là

A.  ( x - 1 ) 2 + y 2 + ( z - 1 ) 2 = 3

B.  ( x + 2 ) 2 + ( y - 2 ) 2 + ( z + 2 ) 2 = 2

C.  ( x - 1 ) 2 + y 2 + ( z - 1 ) 2 = 3

D.  ( x - 1 ) 2 + y 2 + ( z - 1 ) 2 = 12

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

If you take the train, it would be much more convenient

A. If

B. the train

C. would be

D. much

enormous(adj):to lớn,khổng lồ

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of thefollowing questions.

If that was done on a national scale, we would wipe out this infectious disease.

A. establish

B. retain

C. maintain

D. eliminate