____________ you may be right, I can’t altogether agree.
| A．While | B．As | C．If | D．Since |
The surface of the table ______ smooth enough．
| A．hash’t felt | B．isn’t feeling | C．doesn’t feel | D．isn’t felt |
At last，we found ourselves in a pleasant park ________trees providing shade(荫凉)and sat down to eat our picnic lunch．
| A．for | B．from | C．of | D．with |
.Manufacturers should have professional productivity and technical knowledge to ______ the quality of the products.
| A．predict | B．promise | C．guarantee | D．determine |
.It was in the 1990s _______ we were working together ____ we made friends with each other.
| A．that; when | B．when; that | C．that; that | D．when; when |
—Tom, help me buy two tickets for this weekend’s concert online.
—Sorry, there is no ticket _______ online now.
| A．acceptable | B．convenient | C．accessible | D．available |