【简答题】What did the thief take from the shop?
【单选题】— What did you do this morning? — I went _____. [ ]
【简答题】厚度为 2.0m 的烟气层, 测得 有 30% 的光穿过,计算单位厚度上烟气的光学密度为( )及烟气的消光系数为( ) m -1 。结果保留三位有效数字,不用写单位。
【单选题】What is special about the shop's service?
A.
The shop guarantees the battery for a year.
B.
The man will clean it at no extra charge.
C.
The man can repair watches very quickly.
D.
The shop is offering a special discount.
【单选题】—What’s Jack up to in the shoe shop? He’s there for ages. —It’s ______ that he hasn’t decided which pair to buy.
【简答题】有一组样本数据8,x,10,11,9,已知它们的平均数为10,则这组数据的方差s 2 = ▲ .
【判断题】不论在何种账务处理程序下,现金日记账和银行存款日记账都是根据收款凭证和付款凭证逐日逐笔顺序登记的。( )