--____, but usually once a week. ( 天
津)
a. have no idea b. it depends
c. as usual d. generally speaking
【解析】选b it depends,意为“看情况”,它既可单独
使用,也可用于句首。
( )8. when ____ help, one often says "thank you."
or "it's kind of you." ( 福建)
a. offering b. to offer
c. to be offered d. offered
【解析】选d此处,offer与句子的逻辑主语含有被
动含义,因此,用过去分词。过去分词充当状语含有被动
含义。