列车发车时间已到,而发车计时器无显示时,司机应及时向()报告,并根据()指示发车。
参考答案:车站值班员;车站值班员
(3分)某市场销售的化肥硝铵,经检测知道其含氮量为34.3%,则该化肥含硝酸铵的质量分数为___________________。(设其它成分不含氮元素)
— Oh, you have a headache and a cough. ________ have you been like this?
—Three days. [ ]
A. How long
B. How often
C. How soon