与图书相比，期刊的特点之一是（）
A.篇幅不固定，可多可少
B.顺序编号，连续出版
C.开本较大
D.信息量大
参考答案：B
1. John always does his homework ______________ in order not to make any mistakes.
2. It’s ______________ to find any excuse when you do something wrong.
3. The factory makes a new type of cars which produces less air ______________.
4. All the victims were saved and taken to ______________.
5. We all know Mother’s Day is on the ______________ Sunday of May.
一般情况下，中、高速柴油机曲轴箱油的闪点降至（）以下时，则应更换滑油。
A.156℃
B.180℃
C.210℃
D.218℃
