解磷定对哪种有机磷酸酯中毒治疗无效()
A.对硫磷
B.马拉硫磷
C.敌敌畏
D.敌百虫
E.乐果
参考答案:E
.
Nancy enjoyed herself so much ___ she visited her friends in Sydney last year.
A.that
B.since
C.when
D.where
应力放散时,应每隔()m设一位移观测点观测钢轨位移量,及时排除影响放散的障碍。