一批货物a吨,运走b吨,还剩a-b吨.______.
剩下的吨数是:a-b吨.
故答案为:正确.
小明同学做下列化学实验,在他实验报告的数据中,你认为错误的是[ ]
A.用pH试纸测得某盐酸溶液的pH=5.4
B.用10mL的量筒量取某溶液,体积V=8.2mL
C.用托盘天平称量食盐,其质量m=3.4g
D.用温度计测得氢氧化钠固体溶于水后所得溶液的温度为40.2℃
— It's eight o'clock already. Jack _____ be here by now.
— Oh, he told me that he was going to see his dentist and wouldn't be back until ten. [ ]
A. must
B. can
C. should
D. need