有了"北斗", 中国就不必再依赖外国的定位系统了。
China no longer has to ________ ________ foreign positioning systems with Beidou.
他们决定乘坐地铁去鸟巢。
They decide to go to the Bird's Nest ________ ________.
我在外面从不迷路。
I never ________ ________ outside.
The government highly values environmental protection, so we shouldn't throw rubbish about. (改写句子,句意不变)
Rubbish shouldn't ________ ________ about because environmental protection is highly valued by the government.
Tom found it necessary to stop eating wild animals because it could cause a serious disease.（改写句子, 句意不变）
Tom found it necessary to ________ ________ eating wild animals because it could cause a serious disease.
"How can you work out the problem?" Tom asked me. (改写句子,句意不变)
Tom asked me ________ I ________ work out the problem.
