目前发动机上常见的用于降低排放污染的装置有几种？
参考答案：
燃油蒸汽回收装置、废气再循环装置、二次空气喷射装置。
请根据句意及提示，写出所缺单词。
1. He brushes his______ (牙齿) and has a shower every morning.
2. —Are you b______today?
—No. I have nothing to do.
3. The Maths exercises are __ ( not hard; not difficult ) .
4. The car is very (have a high price) .
5. —Which month comes after September?
— .
典型的声带小结为：（）
A.一侧声带的中点处结节性隆起
B.两侧声带的中点处结节性隆起
C.一侧声带膜部的中点处结节性隆起
D.两侧声带膜部的中点处结节性隆起
E.两侧声带膜部前中1／3交界处结节性隆起
