42－____＜34
7＋36＞____
45＋____＜70－6
____－8＜55
俗话说，“女大十八变，越变越好看”，与这种变化有关的主要器官是（ ）
____ did Sarah ____ yesterday?
If you see any litter on the school playground, you'd better _______.
