---- You haven’t got the textbook for my chemistry course yet.
---- I know, and we _____ to get it for the last 5 weeks.
| A．will have been trying | B．have been trying |
| C．will be trying | D．had tried |
.Bicycles made in China are cheaper than ________ made in Japan, but almost as good in quality.
| A．ones | B．it | C．that | D．those |
While working in the countryside , the students ________ a great deal of knowledge on plant life.
| A．looked up | B．picked up | C．put up | D．called up |
By the time she ________ tomorrow, the work ________.
| A．arrives ; will be finished |
| B．arrives ; will have been finished |
| C．will arrive ; will have been finished |
| D．arrives ; will have finished |
Some people waste a lot of food ________ others haven’t enough to eat.
| A．however | B．when | C．as | D．while |
. School children must be taught how to deal with dangerous ________.
| A．states | B．conditions | C．situations | D．positions |