Is _______ here ——-No, Bob is not here.

We had better not bother our professor these days, for he is awfully busy preparing a report _____ atan international conference next month.[ ]

下列各句中，没有病句的一句是（ ）

hat you are our _____ customer, we will allow you a 10% discount if you buy the dress.

Can you come and play football with me—__________, but I have a lot of homework to do.