某同学将水稻、苹果、松树归为一类,把贯众、海带和葫芦藓归为另一类.则他分类的主要依据是( )
A.根的有无
B.种子的有无
C.果实的有无
D.陆生或水生
答案:B
在60克糖水中,糖与水的比为1:5,则糖水中水的质量是( )克。
Your shoes ______ easily but they ______ well.[ ]
A. wear; haven't worn
B. are worn; haven't worn
C. wear; haven't been worn
D. are worn; haven't been worn