Trọng tâm của một vật là gì? Trình bày phương pháp xác định trọng tâm của vật phẳng, mỏng bằng thực nghiệm.

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

I’d have been able to say goodbye to Peter if only _____________ to the airport in time.

A. I get

B. I got

C. I have got

D. I had got

Mark the letter A, B C or D on answer sheet to indicate the answer to each of the following question.

Mr. Peter is the big .................. in the company as he has just been promoted to the position of Managing Director.

A. bread

B. meat

C. cheese

D. apple