The company has a free long-distance telephone number _____ customers may call with any question they have about its products[ ]

It was really a experience. Afterwards everybody was very .

The television has many advantages. It keeps us _____ about the _____ news and also provides entertainment in the house.

is known to all that Taiwan is part of China and it shall not be separated from the mainland

下列各句中，加横线的成语使用正确的一项是（ ）