表示警告、注意的安全色是（）色。
A、红
B、黄
C、绿
参考答案：B
Since nuclear (核) pollution broke out in Japan, in March, 2011, we are all _____ of it very much. [ ]
A. frightened
B. be frightened
C. frightening
D. be frightening
太阳直射点回归运动的周期为365日5时48分46秒，即一个回归年
