()是通过调查表、电子邮件、电话问答的方式进行。但回收率低、回收时间长,所以只适用于对时效性要求不高的信息。
参考答案:问卷法
My aunt always loses her way when she is out by herself because she has no ________ of direction. [ ]
A. sense
B. feeling
C. touch
D. scene
高温快速硫化体系的特点。