【推荐1】It's hard to say what kind of person he is. Sometimes he is very friendly, at other times he _________ be very cold. (用适当的词填空)

【推荐2】单句语法填空(情态动词)
1. In today’s information age, the loss of data ____________cause serious problems for a company.
2. It’s strange that he____________have taken the books without the owner’s permission.
3. I can’t find my purse. I____________have left it in the supermarket yesterday, but I’m not sure.
4. —How do you do, Mr Smith? Thanks for meeting me here.
—You are welcome. You ____________be exhausted after a long walk.
5. —Hi, is that Peter Brown?
—Sorry. You____________(dial) the wrong number.
6. —I didn’t see her in the meeting room this morning.
—She can’t____________(speak) at the meeting.
7. Mike____________have arrived at 8：30 for the meeting, but he didn’t turn up.
8. Often he____________(will) sit for hours doing nothing at all when he was in low spirits.

【推荐3】Sometimes smiles around the world ________ be false, hiding other feelings like anger, fear or worry. (用适当的情态动词填空)