It is sometimes of great _____ to explain to the patient what is happening.
| A．technique | B．signal | C．importance | D．freedom |
The police were seeking more information to find out _______the rich merchant．
| A．who it was that killed | B．who was it that killed |
| C．it was who killed | D．who w as it killed |
Not until he called the secretary three times ______ that the manager went to an important meeting．
| A．did he tell | B．he told | C．was he told | D．he was told |
In one corner of the garden there stands a little board，_______“Keep off the grass．”
| A．On which writes | B．it says |
| C．on which is read | D．which reads |
—Are you still very busy？
—Yes，I ______ the report for the manager and it won’t take long．
| A．have just finished | B．am just finishing |
| C．had just finished | D．am just going to finish |
Are there any restaurants in Beijing _____ authentic Mexican food?
| A．serve | B．that serving | C．that serve | D．serves |