影响氨气脱塔工作效果的因素主要有（），（），（）和（）。
参考答案：PH值；水温；布水负荷；气液比
美国的“硅谷”是世界上最大的高新技术产业区，它位于（ ）
A．洛杉矶
B．底特律
C．旧金山
D．芝加哥
用括号内所给词的适当形式填空。
小题1:My birthday is on the ________ (five) of June.
小题2:Look! There are some books on these ________(shelf).
小题3:There is ________(little) money in this pocket than in the one.
小题4:The book doesn’t belong to ________(he), his book is on his desk.
小题5:At weekends, there are so many ___________(shop) in the supermarkets.
