清扫道岔冰雪或清擦道岔前，应预先向谁取得联系？
参考答案：
应预先向车站值班员或有关人员取得联系，得到同意后方可进行。
—How was the professor's lecture?
—Impressive. Thank you so much for giving me a lift during the rush hours. If not, I ________ the lecture today.
A．couldn't attend
B．might not have attended
C．mustn't have attended
D．can't have attended
什么是实行环境影响评价制度？
