哌替啶的主要代谢途径
A．双氯芬酸钠B．哌替啶C．美沙酮D．异丙肾上腺素E．右丙氧芬
参考答案：A
已知函数f(x)＝cos x(x∈(0,2π))有两个不同的零点x1，x2，方程f(x)＝m有两个不同的实根x3，x4.若把这四个数按从小到大排列构成等差数列，则实数m的值为________．
What would have happened ______,as far as the river bank ?
A．Bob had walked farther
B．If Bob should walk farther
C．Had Bob walked farther
D．If Bob walked farther
