Great changes __________ in this city over the past five years.
| A．took place | B．have been taken place |
| C．were taken place | D．have taken place |
The difficulty which we had __________ with the local people has now been removed.
| A．communicate |
| B．to communicate |
| C．communicated |
| D．communicating |
Studies show that daydreaming contributes significantly to concentration powers and the ability __________ with others.
| A．communicating |
| B．to be communicated |
| C．to communicate |
| D．to communicating |
Parents and children should communicate more to __________ the gap between them so that they can understand each other better.
| A．open |
| B．narrow |
| C．widen |
| D．leave |
Though __________ to see the strangers, the housewife gave them a big smile and said hello.
| A．surprising |
| B．to be surprised |
| C．surprised |
| D．having surprised |
__________，he will not take off his coat.
| A．However it is hot |
| B．However hot it is |
| C．However hot is it |
| D．However is it hot |