C. observed                                                     D. submitted

5.We are sorry for the short delivery by 20 tons. This __________ you some trouble in meeting orders of your clients.

A. must cause                                                  B. must have caused

C. has caused                                                   D. will be caused

6.Please check the enclosed letter of credit to ensure that it __________ your instructions.

A. agrees                                                         B. agrees to

C. agrees upon                                                 D. agrees with

7. Generally speaking, a growing demand can __________increased price.

A. result                                                          B. result from

C. result for                                                     D. result in

8.We are enclosing a list __________ our business activities.

A. showing                                                      B. shown