Chiếu xiên một chùm sáng hẹp gồm hai ánh sáng đơn sắc là vàng và lam từ không khí tới mặt nước thì

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Choose the best answer for the following sentence:

  Since 1980, scientists all over the world ________________ a lot of things to fight against AIDS.

    

• Choose the best answer for the following sentence:

  At present, they ___________________ with the medicines to cure this terrible disease.
   

• Choose the best answer for the following sentence:

  Many people __________________ of malaria, smallpox, before the process of
  vaccination was invented in the 19^th century.
   

• Choose the best answer for the following sentence:

  Our government ___________________ a system of private schools in the new future.
   

• Choose the best answer for the following sentence:

  The doctor said that his appetite ____________________ him restore his health quickly.
   

• Choose the best answer for the following sentence:

  Now my sister _____________________ a bicycle of her own.
   

• Choose the best answer for the following sentence:

  Before the Prime Minister leaves Hanoi, he ________________ several talks.
   

• Choose the best answer for the following sentence:

  We had just got out of the car when it ____________________ to set fire.
    

• Choose the best answer for the following sentence:

  A ban was given ___________ all trade in ivory in 1989.

• Choose the best answer for the following sentence:

  John, as well as I, ___________________ a student.