The word "observances" in the last paragraph is ______.
A. rituals
B. beliefs
C. traditions
D. freedom
查看答案
Which of the following statements is NOT true according to the passage？
A. Drug use among American teens is increasing dramatically despite years of antidrug campaigns.
B. Drugs are more readily available and used by youth at a younger age than ever before.
C. Few parents warn their children often about the dangers of drugs.
D. Even policymakers, school officials find it necessary to reexamine current drug prevention efforts.
On the forth paragraph, the word "extinction" in the sentence "Climate changes caused the
A. evolution
B. distinction
C. production
D. depopulation
While other animals use a limited range of sounds or signals to communicate, humans have developed complex systems of language in order ______.
A. to hunt animals
B. to find food
C. to communicate
D. to show the feature of every human society or culture
微信支付 
支付宝支付