遇险呼叫尝试时，成功率最高的是：（）
A.单频尝试
B.组合频率尝试
C.多频尝试
D.不定
参考答案：B
浏览55页3a部分，判断正T，误F。
( )1. Robert likes thrillers but he doesn't like action movies.
( )2. Maria likes comedies but she doesn't like thrillers.
( )3. Michele likes comedies and documentaries.
( )4. Guo Peng likes comedies and Beijing Opera.
由受热物质微粒的流动来传播热能的现象，叫（）。
