A:do his homework
B:do his homeworks
C:does his homework
D:does his homeworks
我们食用的菠菜、大葱都含草酸(C2H2O4).计算:
明朝时期,收集了1892种药物,11096则药方的“医学巨典”是( )
读“某大洋副热带和副极地海区的温度曲线图”,完成下面小题。
温度分布由南向北的排列顺序与时间对应正确的是( )