补肾阳，益肾精，强筋骨，祛风湿的药物
A. 补骨脂
B. 菟丝子
C. 肉苁蓉
D. 巴戟天
E. 核桃仁
When towing，the least amount of tension will be on each bridle leg when the two legs ().
A. form. a large angle with each other
B. form. a small angle with each other
C. are of unequal length
D. are joined by a fishplate
爆破地点附近20m以内风流中甲烷浓度达到()时，严禁爆破。
A. 0.5%
B. 0.75%
C. 1.0%
下列哪一种涂料为进行合适固化很可能需要水分：()
A. 聚氨酯涂料
B. 胺固化环氧涂料
C. 无机硅酸锌涂料
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