Scientists ______ thousands of chemicals before they decided on the right one in the end.
| A．tried out | B．found out |
| C．worked out | D．turned out |
Little Tom was so enthusiastic about learning Chinese and after six months, he could speak it ______ fluently.
| A．professionally | B．correctly | C．pretty | D．locally |
This is a complex operation. A team of nurses _____ the doctor in performing the operation.
| A．trained | B．assisted | C．interviewed | D．added |
The conflict between economic development and environmental protection, if not appropriately _________, can cause disastrous consequences in daily life settings.
| A．being managed | B．to manage |
| C．managed | D．managing |
People are always coming in here borrowing my hammer, you know, to fix a cart wheel or ______.
| A．anything | B．something |
| C．everything | D．nothing |
The WHO ________ eat less bacon and other preserved meat because they can cause cancer.
| A．appeals people to | B．appeals to people to |
| C．calls in people to | D．calls on people |