If we get nervous when speaking, it means we are poor speakers.
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It is estimated that careful preparation can reduce anxiety by as much as 75 percent.
A. 对
B. 错
Recording ourselves is very important, and we should watch our videos at least 3 times.
A. 对
B. 错
If you get nervous, there is no need to look at the audience.
A. 对
B. 错
. 血清中含量最高的Ig是（ ）
A.IgM
B.IgA
C.IgG
D.IgD
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