Chu kì bán rã của chất phóng xạ là 20 năm. Sau 80 năm có bao nhiêu phần trăm chất phóng xạ đó phân rã thành chất khác:        

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Choose the best answer for the following sentence:

  ____________ is a kind of music, emerging in the early 1900s, usually with a strong beat and simple tunes, created with electrical or electronic equip¬ment and easy to listen to and remember.

   

• Choose the best answer for the following sentence:

  _____________ is a kind of popular music developed in the 1950s which has a strong beat and is played on electrical instruments.

   

• Choose the best answer for the following sentence:

  Romantic music often ____________ the listeners’ emotion.

   

• Choose the best answer for the following sentence:

  They intend to set up some _____________ discotheques for those who do not smoke.

   

• Choose the best answer for the following sentence:

  - ________________?

  - Classical music.

   

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

  soothe                    anthem                  further                within

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

  essential                    enter                   treat                      entertain

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

  visual                     music                    used                     names

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

  main                  entertain                  maintain                   certain

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

  aware                     share                     are                   compare