农村公路主要供机动车辆行驶并达到一定技术标准。县道一般采用三、四级公路标准;乡道采用( )标准。
A.三级公路 B.四级公路C.三、四级公路 D.四级公路或等外路
参考答案:D
小刚站在平面镜前4m处,另一位同学将平面镜向远离小刚方向移动了1m,则小刚同学在平面镜中两次所成的像之间的距离是( )
A.1m
B.2m
C.3m
D.4m
用适当的介词或副词填空。
1. If you cheat in the exam, you'll never get away____it.
2. You have got____all your difficulties.
3. Don't you think it's time we got ____the work?