短波发信天线必须与发信功放输出（）相匹配。
A.功率
B.方式
C.阻抗
D.电压
参考答案：C
_____ at the seaside! [ ]
A. How fun the children had
B. What a fun the children had
C. How fun had the children
D. What fun the children had
应激反应
