I can't find Mary downstairs.She ____ her homework upstairs.A must do Bmust be doing C must havedone Dcan't do答案是B,为什么不选A

I can't find the lbrary .What____ I ______(do)I can't find the lbrary .What____ I ______(do) I can’t find I can't find I can't find Mary downstairs.She ____ her homework upstairs.A must do Bmust be doing C must havedone Dcan't do答案是B,为什么不选A 反义疑问句 I don't think Mary can swim,can she/do you? I can' t find my I can't find you I can 't find ___shoes. I can't find my cat,Do you find it a___ How can I do? I can't find the way! 什么意思 I can't find the way to Xinhua Bookstore.What ( ) I do?急用! I can't find my cat .Do you see it a____? I can't find my cat.Do you see it a----? I can't ___(find)my ticket.What __I ___(do)?麻烦解释一下，谢谢 I can't find my English book. I can 't find the key_____my house I can‘t find my giasse是什么意思 I can't find you是什么意思