【单选题】听力原文:M1: Jack, when you are done with the paper, can I read it? I need to check something in it. M2: Here, you can take it, Peter. I'm done with it. Oh, by the way, how is Carol working out in her new...
A.
Jack's promotion to a managerial position.
B.
How a co-worker is adjusting to a new position.
C.
What to do about one of the team members who is not doing a good job.
D.
Where to place a shy worker who is new to the company.
【简答题】什么叫基准物质?作为基准物质必须具备什么条件?标定碱标准溶液时,邻苯二甲酸氢钾(KHC8H4O4,M=204.23 g·mol-1)和二水合草酸(H2C2O4·2H2O,M=126.07g·mol-1)都可以作为基准物质,你认为选择哪一种更好?为什么?
【单选题】Jack can read and write. He is ______ 5 years old.
【判断题】在常温常压下,氮气是无色、无味、无嗅的惰性气体。( )
【判断题】四氟乙烯常温常压下为无色无味的气体,比空气重2倍,是制取全氟丙烯单体的原料气。
【单选题】下列说法中,能准确描述氧气化学性质的是( )
D.
氧气是一种化学性质比较活泼的气体,可以和多种物质发生氧化反应
【判断题】液氯常温下为淡黄色、无味有毒的气体。()