VOA慢速英语:China Says It Will Return US Drone Taken from South China Sea

短语讲解：

1. China says naval officials decided to take the object to make sure other ships could pass safely through the area.

make sure 把事情弄清楚，核实或查明某事物;
例句：Please make sure that the door is locked.
请弄准门确实是锁好了。

2. Chinese officials later discovered it was an unmanned underwater vehicle belonging to the United States.

belong to 属于
例句：I belong to no party.
我不属于任何派别。

3. U.S. officials have said the drone was operating in the area to collect scientific information related to water conditions and temperature.

relate to 涉及; 同…有…关系
例句：How do these relate to the product being designed?
这些经历同将要设计的产品有什么关系？

4. U.S. defense officials confirmed they were in contact with China about the issue.

in contact with 与…在接触中
例句：Are you in contact with him now?
你现在与他有联系吗?

5. The United States and other countries have raised concerns about China's growing military presence in the South China Sea.

concern about 使（自己）关心…
例句：She showed great concern about you.
她很为你担心。