单项选择题 W: I am so excited just to think about it! This is my first trip to Paris. I want to visit all the interesting places there. But I am afraid that I can’t find my way around there.M: Don’t worry about that. Just give me a call when you have trouble. I’ll be glad to show you around. I am so familiar with these places.Q: What does the man offer to do for the woman?（）

单项选择题 一般在竣工之前，业主提供的工程预付款和进度款总额不超过合同价的（ ），其余尾款是工程竣工结算时支付的款额。

单项选择题 水和无机盐能进入细胞而有害物质不能进入，这主要是由于（）的作用。