Scientists are convinced _____ the positive effect of laughter _____ physical and mental health．
| A．of; on | B．by; in | C．of; at | D．on; at |
The manager was concerned to hear that two of his trusted workers ______.
| A．will leave | B．are leaving | C．have left | D．were leaving |
He got himself into a difficult situation ________he must make a final decision all by himself.
| A．which | B．what | C．when | D．where |
I bought my younger sister a toy with my pocket money，________that is cheap but beautiful.
| A．one | B．the one | C．this | D．that |
At the meeting，Tom ________an idea about how we could get enough money to help those in trouble.
| A．came up to | B．came up | C．came out | D．came up with |
________taller of the two girls is my daughter who was made ________monitor yesterday.
| A．The；the | B．The；/ | C．A；a | D．A；/ |