珠光体耐热钢焊接时的主要工艺措施是预热、焊后缓冷、焊后热处理，采用这些措施主要是防止发生冷裂纹（延迟裂纹）。
参考答案：对
—Was the trip pleasant when you vacationed in the mountain village last summer?
—No，it__________for four days when we arrived，so the roads were very muddy.
A．was raining
B．would be raining
C．had been raining
D．have rained
鼻窦恶性肿瘤治疗首选以药物为主的综合治疗。
