(____) These are all books about science.
(____) That's a good idea.
(____) Let's put them on this shelf.
(____) We can put them on Shelf B.
(____) Let's make a home library.
人居环境即人类的居住环境,包括____要素和____要素两部分。
设a=∫0πsinx+cosxdx,则二项ax-1x5式展开式中x2项的系数是( )
中东地区一些国家的人们夜晚常把床铺安排在屋顶上,这是因为( )
小小蝌蚪在水中游来游去,招人喜爱.你能说出幼体蝌蚪与成体青蛙的显著区别吗( )