Although the causes of cancer_____, we do not yet have any practical way to prevent it.
| A．are being uncovered | B．have been uncovering |
| C．are uncovering | D．have uncovered |
Look at the trouble I am in! If only I __________ your advice.
| A．followed | B．would follow | C．had followed | D．should follow |
The doctor did a lot to __________ the patient's fear __________ he would die of cancer.
| A．induce； that |
| B．reduce;that |
| C．induce；ofwhich |
| D．reduce； which |
They use computers to keep the traffic _________ smoothly.
| A．being run | B．run | C．to run | D．running |
The flowers _________ my mother, but my sister thought they were for her and took them.
| A．were intended for |
| B．intended for |
| C．intended to give |
| D．intended giving |
She had just finished her homework_________her mother asked her topractice playing the piano yester-day.
| A．when | B．while | C．after | D．since |