Remove the batteries when they become weak or when the unit is not in use for extended periods. This will damage to the unit from battery leakage at such times.
| A．disappoint | B．concern | C．instruct | D．prevent |
“How can we go outing in this kind of weather!”! Bob said,__________ out of the window.
| A．looking | B．looked | C．to look | D．having looked |
All the preparations for the work_______, we’re ready to start.
| A．are completed | B．have been completed |
| C．completed | D．had been completed |
Zhuhou, _______ on the Xiang River, is an important city, second only to Changsha.
| A．located | B．locating | C．being located | D．to be located |
The flowers his friend gave him will die unless______ every day.
| A．watered | B．watering | C．water | D．to water |
The boy wanted to ride his bicycle in the street, but his mother told him _____.
| A．not to | B．couldn’t | C．not do it | D．do not to |