---Could you let me know ________ yesterday ? ---Because the traffic was heavy .
-Can you tell me why you learn English so well?-It’s very simple._____ you work,______ grades you will get.
-What would you do if you _____ the traffic accident?-I would ______.
-Do you know that there are many different ____ animals in the zoo?—Yes,I do. And I also know that some of them are_____scaring.
-______ I do the laundry first?-No,you _____. You can do your homework first.
-Hey, Molly, You______ on the phone just now. But you weren’t here and the man left a phone number.-Oh? I was in the library.