在家里和商场里进行调查，有多少种防紫外线的用品，并了解它们防紫外线的原理．
答：例如防紫外线眼镜．原理是玻璃对可见光虽是透明的，却对紫外线有很强的吸收作用．
The government has hardly taken measures to crack down on these crimes when new ones occurred.
A．Hardly had the government taken
B．The government took hardly
C．Hardly the government had taken
D．The government is hardly taking
某汽修车间为等高单层双跨排架钢结构厂房，梁柱构件均采用焊接实腹H型截面，计算简图如下图所示。梁与柱为刚性连接，屋面采用彩钢压型板及轻型檩条。厂房纵向柱距为7.5m，柱下端与基础刚接。钢材均采用Q235-B，焊条为E43型。
B轴线中柱上端与屋面梁刚接，上、下段柱截面特性如下图所示。试问，下段柱在排架平面内的计算长度系数应与下列何项数值最为接近？（）
提示：
①无屋盖纵向水平支撑；
②μ1=0.56。
A.1.29
B.1.47
C.1.66
D.1.84
