His aunt’s letters him of those beautiful days when they used to live together in his hometown.
| A．call up | B．call for | C．call on | D．call at |
_A Chinese runner,Liu Xiang,rushed to the ending line _______a surprising speed.
| A．at | B．by | C．through | D．with |
_The work is easy for an expert _______it is difficult for an inexperienced person.
| A．because | B．therefore |
| C．while | D．unless |
_You must get up early in the morning, ______we’ll have to leave without you.
| A．and | B．but | C．or | D．so |
_Stressful environments lead to unhealthy behaviors such as poor eating habits,which_______increase the risk of heart disease.
| A．in turn | B．in return |
| C．by chance | D．by turns |
_ I was_______ the point of telephoning him when his letter arrived.
| A．in | B．to | C．at | D．on |