---Will you tell him I have come to visit him? ---All right, I will ______ he comes back.
| A．instantly | B．frequently |
| C．constantly | D．suddenly |
Although the causes of cancer ________, we do not yet have any practical way to prevent it．
| A．have uncovered | B．have been uncovering |
| C．are uncovering | D．are being uncovered |
Someone who lacks staying power and perseverance is unlikely to _________ a good researcher．
| A．make | B．turn | C．get | D．grow |
They _________ two free tickets to Canada, otherwise they'd never have been able to afford to go．
| A．had got | B．got | C．have got | D．get |
—Have you been wasting time on computer games again?
—________．I've been studying a lot and I need a break．
| A．No way | B．Not really | C．I don't agree | D．I couldn't agree more |
________ walk is expected to last all day, so bring ________ packed lunch．
| A．A ; a | B．The; 不填 | C．The; a | D．A ; 不填 |