Cho phản ứng của oxi với Na. Phát biểu nào sau đây không đúng?

A. Na cháy trong oxi khi nung nóng.

B. Lớp nước để bảo vệ đáy bình thủy tinh.

C. Đưa ngay mẫu Na rắn vào bình phản ứng.

D. Hơ cho Na cháy ngoài không khí rồi mới đưa nhanh vào bình.

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

I’m sure Luisa was very disappointed when she failed the exam.

A. Luisa must be very disappointed when she failed the exam.

B. Luisa must have been very disappointed when she failed the exam.

C. Luisa may be very disappointed when she failed the exam.

D. Luisa could have been very disappointed when she failed the exam.

After a six-year relation, Martha and Billy have decided to ________ . 

A. break the bank 

B. tie the knot 

C. turn the page 

D. make ends meet