Jim records his physical training every time so that he can it and think about how he should improve it the next day.
A:contribute to
B:lead to
C:attend to
D:refer to
下列是人体中几种体液的正常pH,酸性最强的是( )
计算:﹣45×(19+113﹣0.4)
如图,DE∥BC,EC=AD,AE=2cm,AB=7.5cm,求DB的长.
具有下列染色体数一般不可能是体细胞的是( )