I used the bag to protect my face from the smoke and heat.

The room was full of people and smoke. She started to feel ______ with the heat insideA．op

Firewall is a （74） mechanism used by organizations to protect their LANs from the Internet

People have proved______to be true that the heat we get from coal and oil comes from the s

We have made up laws to protect the water from being polluted and the animals _____

Communication through writing emancipates man from the constraints imposed by the face－to－face distance and the （) of time.

Communication through （) emancipates man from the constraints imposed by the face－to－face distance and the spontaneity of time.