Keep on trying. Never _________. I am sure you will succeed sooner or later.
| A．lose your heart | B．lose hearts | C．lose one’s hear | D．lose heart |
.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 |