检测蛋白质腐败变质最敏感的指标是()。
A.微生物
B.物理
C.化学
D.感官
E.酸价
参考答案:D
— Why are you so busy, Mike?
— I ____ a novel these days. [ ]
A. was writing
B. wrote
C. am writing
D. have written
— Can you __ what these characters on the rock are?
— Not really.
A.carry out
B.make out
C.come out
D.go out