dùng "tích trung tỉ bằng tích ngoại tỉ"       

nhiet do tang thi no ra va co lai thi nhiet do giam

vi khoi luong rieng cua chat long ti le thuan voi nhiet do

50 do. qua trinh nong chay keo dai tu 3 den 6 phut

cau niet ke ruou dung de do nhiet do ko khi

hinh nhu co mot cau sai

CAI AY AY DO

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

Nothing unusual happened, _______?

A. did it

B. didn’t it

C. did they

D. didn’t they