Mr Green is very strict his students, and he is also strict his work.
A：in; with
B：with; in
C：with; with
D：in; in
我会选词填空。
微笑 欢笑
爸爸脸上的____消失了，严肃地说：“做什么事都要认真。”
浪花____着向前奔去。
转基因技术给人类带来巨大利益的同时也带来了潜在的威胁和负面影响．
