砌体工程中宽度超过（）mm的洞口上部，应设置过梁。
A.300
B.400
C.500
D.600
参考答案：A
The government officials made a quick reaction _______ the news of the earthquake.[ ]
A. having heard
B. heard
C. being heard
D. on hearing
放疗最严重的晚期反应是（）
A.假性进展
B.脑白质病
C.放射性坏死
D.脱髓鞘
E.神经认知功能损伤
