Sam’s been doing his homework since 8: 00, ______ he?A. isn’t B. doesn’t C. hasn’t
Mr Wu said he didn’t know much about computers, but he’d try and help us ________.
I’m looking forward to ________ from you.
________ the kind man, the poor boy can go to school.
—Are you ready for your trip? —Yes. I’m ________ my suitcase.
When you travel to a city, you’d better buy a ________to get more information about it.