4. A speaker's credibility can be based on research or ___________________ knowledge. It is a matter of being qualified to speak on a given topic.
A.secondhand
B.indirect
C.firsthand
D.peer
- · 有3位网友选择 C,占比33.33%
- · 有2位网友选择 A,占比22.22%
- · 有2位网友选择 D,占比22.22%
- · 有2位网友选择 B,占比22.22%