① What are you doing? ____ A. No，she isn't.
② What is your mum doing? ____ B. Yes I am.
③ Can I use your pen? ____ C. I'm cleaning my room.
④ Is Sarah reading a book? ____ D. She is cooking fish.
⑤ Are yoy doing homework? ____ E. Sure.
— ________book is this? —It's my book.
已知m∈R，当点（﹣4，6）到直线l：（m﹣2）x﹣y+3m+2=0的距离最大时，m的值为（ ）
“流水线操作生产”、“多媒体教学”、“提倡低碳环保”。这些现象主要集中反映出科技革命（ ）
我们常说的“藕断丝连”中的“丝”属于什么组织（ ）
