题目

草履虫对氧气的摄入以及二氧化碳的排出主要通过（ ） A . 伸缩泡 B . 收集管 C . 表膜 D . 胞肛 答案：C用括号中所给单词的适当形式填空。1．Li Ming often ___________ (go) to school by bike.2．How many ____________ (box) do you have?3．This is my friend. ___________ (he) name is Tom.4．I am _____________ (wash) the gloves now.5．I want to be a bus __________ (drive).