Scientists are convinced the positive effect of laughter physical and mental health.
| A．of; at | B．by; in | C．of; on | D．on; at |
The news came as no surprise to me. I _______ for some time that the factory was going to shut down.
| A．had known | B．knew | C．have known | D．know |
My mind wasn’t on what he was saying so I’m afraid I _______ half of it.
| A．was missing | B．had missed | C．will miss | D．missed |
With more forests being destroyed, huge quantities of good earth _______ each year.
| A．is washing away | B．is being washed away |
| C．are washing away | D．are being washed away |
—What were you up to when she dropped in?
—I _________ for a while and __________ some reading.
| A．was playing; was going to do | B．played; did |
| C．had played; was going to do | D．had played; did |
—Have you heard from Janet recently?
—No, but I ______ her over Christmas.
| A．saw | B．will be seeing | C．have seen | D．have been seeing |