The following are all cited as advantages of e-book EXCEPT______.
A.imaginative design
B.environmental friendliness
C.convenience for readers
D.multimodal content

判断题改善旅游接待地原住民的生活质量是旅游业可持续发展的目标之一。 正确 错误

未分类题Which of the following interpretations of the biologists' theory about melatonin is INCORRECT?A.The production of melatonin in our bodies varies at different times.B.Melatonin is more likely to cause sleepiness in our bodies.C.The reduction of melatonin will cause wakefulness in our bodies.D.The amount of melatonin remains constant in our bodies.

单项选择题紧急呼叫(SOS)需要进行附着以后才能发起的网络服务（ ）

未分类题Which of the following can best sum up the author's overall reaction to her adult son's positive response to spring cleaning?A.Surprised and skeptical.B.Elated and hesitant.C.Relieved and optimistiC.D.Optimistic and hesitant.

单项选择题一组数据的分布曲线呈双峰状态，据此可以推测该组数据中可能有两个（2012年全国统考） A、中数 B、众数 C、平均数 D、几何平均数