钢结构连接中所使用的焊条应与被连接构件的强度匹配，通常在被连接构件选用Q235时，焊条选用（)。
A. E43
B. E50
C. E55
D. 三种均可
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摩擦型高强螺栓所受拉力应低于其预拉力的（)。
A. 1.0倍
B. 0.5倍
C. 0.8倍
D. 0.7倍
Directions: For this part, you are allowed 30 minutes to write an essay on the importance of having a sense of social responsibility. You should write at least 150 words but no more than 200 words.
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