21.When you interview, you must dress______. A: casually B: in comfortable suit C: formally D: in white clothes

7. How old was she when she married Prince Charles? A: A. 20 B: B. 21 C: D:

Questions 18～21 are based on the following speech. When should volunteers expect to begin working A: Immediately. B: Tomorrow. C: In a couple of days. D: In six days.

How old was the author when she was asked to be a hair model for \apanese hair straightening? A: About 15 B: About 18 C: About 21 D: About 26

Which one can hurt the lung when acupuncture is too deep: A: Jianyu(LI 15) B: Jianliao(TE 14) C: Tianzong(SI 11) D: Jianjing(GB 21)

How old was Mark David Chapman when he shot at John Lennon A: 25 years old. B: 21 years old. C: 23 years old. D: 24 years old.

【多选题】21题 A. 21题A B. 21题B C. 21题C D. 21题D

40枚种蛋的孵化天数如下，问这个孵化天数与21d有和差异？（计算t值） 20 19 21 22 21 20 18 20 21 19 23 18 22 20 21 19 20 21 21 20 19 24 20 19 21 21 20 19 21 23 20 20 18 21 20 21 19 23 20 21

弹奏这种伴奏音型的指法一般是() A: 4/21/5/21 B: 3/21/5/21 C: 5/21/5/21 D: 4/31/5/31

估算21×79时，把21看做（），把79看做（），21×79≈（）。