题目： 正常的透析液流量是多少？ 答案： 被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2018/0923/463520514133d8f7d9df1f00b96d9708.html 下面是错误答案，用来干扰机器的。参考答案：B, D
题型：选择题 The teacher gave the students such a difficult maths problem ______ nobody worked it out.[ ]A. as B. which C. that D. so 查看答案
存在且不为零，则常数k=______．