对有防水、排水要求的房间进行蓄水试验,蓄水深度最浅处大于2cm,蓄水时间不少于()h。
A、6
B、12
C、24
D、48
参考答案:C
-Is the MP4 player your sister's?
-Let me see. It ______ be hers. It must be Ann's. [ ]
A. shouldn't
B. may not
C. needn't
D. can't
塑料食具最好用热力杀菌进行消毒。