【单选题】— Good morning, sir. May I help you? —__________.
C.
Thanks. I’m just having a look
【简答题】2005年诺贝尔化学奖授予三位在绿色化学领域有突出成就的科学家,绿色化学核心是实现零排放,而加成反应和化合反应实现了零排放.重氮甲烷在有机合成中有重要应用,可以用来合成甲醚、羧酸、酯类等重要有机产物.重氮甲烷的分子结构可以表示为 CH 2 -N≡N,在其分子中,碳原子和氮原子之间的共用电子对是由氮原子一方提供的. (1)重氮甲烷的电子式为______. (2)重氮甲烷在受热或光照时容易分解放出氮...
【单选题】听力原文:M: May I help you? W: Yes, I want to buy some shoes to replace the ones I'm wearing. M: What's wrong with them? W: They are too old and shabby. M: I can see they have simply been worn out. Would ...
A.
Similar to what she wears.
C.
A little bit dressier.
【单选题】听力原文:M: May I help you? W: Yes, I want to buy some shoes to replace the ones I'm wearing. M: What's wrong with them? W: They are too old and shabby. M: I can see they have simply been worn out. Would ...
C.
They were of a dull colour.
D.
They were out of style.
【简答题】A.May I help you? B.What's wrong? C.I'm glad to see you.
【单选题】丁烷分子中,以C2与C3之间的σ键为键轴所形成的4种构象异构体: (I)对位交叉式;(II)部分重叠式;(III)邻位交叉式;(IV)全重叠式。按能量由低到高排序正确的是:
【单选题】听力原文:W: Hello, University of Sidney. May I help you? M: Yes. I'm looking for information on courses in computer programming. W: Do you want a day or evening course? M: Well, it would have to be an eve...
A.
To inquire about computer programming courses.
B.
To inquire about the time of the lecture.
C.
To buy some computer books.
【单选题】丁烷分子中,以 C 2 与 C 3 之间的 σ 键为键轴所形成的 4 种构象异构体:( I )对位交叉式;( II )部分重叠式;( III )邻位交叉式;( IV )全重叠式 。 按能量由低到高排序正确的是:( )
【单选题】听力原文:M: Welcome, Miss. May I help you? W: I hope so. I want a lipstick. M: Do you have any particular brand in mind7 W: I like Lyfel very much. M: We have different shades of Lyfel lipstick. May I kno...
【单选题】听力原文:W: City utility department, how may I help you? M: Yes, I'm new here and trying to figure out how garbage and recycle collection work. My understanding is that garbage is collected on Wednesdays,...
A.
House waste collection
B.
Garbage collection times