___the general state of his health,it may take him a while to recover from the operation
| A．Given |
| B．To give |
| C．Giving |
| D．Having given |
When you stand on the top of the mountain and overlook the surrounding scenery, you will find it is ______ to climb it up with effort.
| A．worth | B．worthy |
| C．possible | D．worthwhile |
A harmonious society is very important, so all the laws must be strictly______.
| A．watched | B．observed |
| C．carried | D．handled |
It is so noisy in the restaurant and hard for us to ________ a conversation.
| A．go on | B．keep on | C．carry on | D．take on |
Studies show that people are more_____ to suffer from back problems if they always sit before computer screens for long hours.
| A．likely | B．possible |
| C．probable | D．sure |
A survey of health researchers ______ that four hours of exercise every week ____ good for our health.
| A．show; are | B．shows; is |
| C．show; is | D．shows; are |