未知题型 -Hello, may I talk to John please? -( ).Sorry, he is busy at the momentB: No, you can'tC: Sorry, you can'tD: I don't know

未知题型 He is always getting ( )me for minor mistakes.forB: atC: awayD: over

单项选择题 打开过的无菌包若未受污染有效时间为：