NASA's Constellation Programme would be cancelled mainly because______
A.there were more important space missions
B.the space agency lacked funding for the programme
C.the current shuttle missions would continue
D.Congress failed to pass President Obama's budget

未分类题When you have finished with the book, don't forget to return to Tim, ______?A.won't youB.don't youC.will youD.do you

单项选择题乳牙期前牙反 牙合 的矫正年龄一般为 A 1-2岁 B 2-3岁 C 3-6岁 D 6岁以上

未分类题The following are all cited as advantages of e-book EXCEPT______.A.imaginative designB.environmental friendlinessC.convenience for readersD.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.