()指的是组成轮系的齿轮中至少有一个齿轮几何轴线的位置不固定,而是绕着其它定轴齿轮轴线回转的轮系。
A、滚轴轮系
B、周转轮系
C、定轴轮系
D、混合轮系
参考答案:B
句型转换。
1. We have classes from Monday to Saturday.We have no class on Sunday.( 改为同义句)
We have _____ _____Sunday
2.My mother says she wants to go to Shijiazhuang.( 对画线部分提问)
____ _____your mother_______?
3.He'll come back.He says.(改为宾语从句)
He says that he_____ ______back.
4.I counted a lot.I was a little girl.(改为含有when引导的时间状语从句)
I counted a lot_____ ______ _____a little girl.
5.I like school very much this year.(改为否定句)
I_____ ______school very much this year.
简答Bonczek三系统结构的优缺点。