重点讲解：
1. roll out
推出；公布；
例句：The new model is to be rolled out in July.
这种新型号将在七月份推向市场。
2. call on sb. to do sth.
要求：呼吁：号召；
例句：I also call on all people in society who are capable of supporting them to love those children.
我也呼吁所有能支持到他们的人去关爱这些孩子。
3. so as to do sth.
（用于引出原因）为了；以便；
例句：The test questions are kept secret, so as to prevent cheating.
为了防止作弊，考试的题目是保密的。
4. instead of
代替…；而不是…；
例句：Instead of making progress, my work actually seems to be going backwards.
我的工作不但没有进步，实际上像是在倒退。
