【单选题】已知函数y= k x (k>0)经过点P 1 (x 1 ,y 1 ),P 2 (x 2 ,y 2 ),如果y 1 <y 2 <0,那么( )
【简答题】钩藤的降压有效成分是{1}和{2},遇热易{3}。
【单选题】黏膜淋巴组织中的 B 细胞主要分泌的抗体属于哪一类:
【简答题】在GF(p)上,若已知a及x,计算ax mod p=y是很容易的,但是若已知y及a,反求x的过程称为()的计算问题。
【简答题】根据课文填空,每空一词。 What are some of the problems caused by chemical fertilizers? First, they damage the land l_____ killing the helpful bacteria and pests as well as the harmful ones. Chemicals also stay in...