为了提高问卷的效度，设计问卷时应着重抓好（）设计这一环节。

搜题请搜索小程序“爱下问搜题”

问题填空题

答案

参考答案：目标体系

选择题

— Tom is never late for work. Why is he absent today ?

— Something _______ to him.

A．must happen

B．should have happened

C．could have happened

D．must have happened

问答题简答题

简述影响皮脂分泌的因素。