[单项选择]A. Birds use their beaks to clean their feathers.
B. Preening is very important to birds.
C. The habits of birds are interesting.
D. How birds clean their feathers.

[单项选择]You may use the room as you like （　） you clean it up afterwards.
A. so far as
B. so long as
C. in case
D. even if

[单项选择]You may use the room as you like ______ you clean it up afterwards.
A. so long as
B. so far as
C. in case
D. even if

[填空题]not clean

[单项选择]
Birds Began as Feathered Reptiles
Birds evolved during the great reptilian radiation of the Mesozoic era. Amniotic eggs and scales on the legs are just two of the reptilian features we see in birds. But modern birds look quite different from modern reptiles because of their feathers and other distinctive flight equipment.
Characteristics of Birds
Almost every part of a typical bird’s anatomy is modified in some way that enhances flight. The bones have an internal structure that is honeycombed, making them strong but light. The skeleton of a frigate bird, for instance, has a wingspan of more than 2 meters but weighs only about 113 grams. Another adaptation reducing the weight of birds is the absence of some organs. Females, for instance, have only one ovary. Also, modern birds are toothless, an adaptation that trims the weight of the head. Food is not
A. They developed a skeleton with fewer bones.
B. Their organs became smaller over time.
C. Most of their weight was distributed in their heads.
D. Teeth were replaced by a beak made of keratin.

[单项选择]
Years ago, social scientists introduced the broken-windows theory of crime control, which assumed that if a neighborhood looked orderly and cared for—with no broken windows—potential wrongdoers would be dissuaded from committing crimes there. Now psychologists have proposed a similar theory, which suggests that people can be induced to behave morally when their environment smells as clean as it looks.
It’s the Macbeth principle of morality, says Katie Liljenquist, professor of organizational leadership at Brigham Young University’s Marriott School of Management and lead author of the new study, to be published in Psychological Science. "There is a strong link between moral and physical purity that people associate at a core level. People feel contaminated (受污染的) by immoral choices and try to wash away their sins," says Liljenquist. "To some degree, washing actually is effective in relieving
A. potential wrongdoers would be dissuaded from breaking windows.
B. psychologist would suggest people behave morally.
C. it is less likely that people would commit crime there.
D. it would smei1 as clean as it looks.