单选题 Stressful environments lead to unhealthy behaviors such as poor eating habits 

which__ incrcase the risk of heart 

disease.

单选题 He was proud of being chosen to

participate in the game and he us that he would try as hard as possible.

单选题 Communication is the process of 

transmitting a message from a(n) ___ to 

an audience via a channel.

单选题 A well-written composition ______good 

choice of words and clear organization

among other things.

单选题 A house with a dangerous gas_____

cannot be broken into immediately.

单选题 We must _____ that the experiment is 

controlled as rigidly as possible.

单选题 Notebooks, textbooks, and school 

magazines were accidentally ____all over the floor.

单选题 She spoke so __at the conference, as 

though the said issue was of little

importance