下述因素均可引起小细胞支气管癌，除了
A．铬与镍蒸气
B．吸烟
C．砷
D．石棉
E．硅沉着病(原称矽肺)
参考答案：E
点P（x+1，y-1）关于原点对称的点P′的坐标为（-3，-5），则x+y=（ ）。
27．To tell you the truth，the accident and the damage______resulted in frightened me so much that I almost have given up driving ever since．
A．that
B．it
C．which
D．What
