首页
登录
职称英语
[originaltext]M: Want to go out and get something to eat?W: I can’t. I have a
[originaltext]M: Want to go out and get something to eat?W: I can’t. I have a
游客
2024-02-13
58
管理
问题
M: Want to go out and get something to eat?
W: I can’t. I have a chemistry midterm on Monday and a German exam on Tuesday.
M: I have a geology exam Monday myself, but I think I’m ready for it.
W: What kind of exam is it going to be—multiple choice or essay?
M: Neither. The professor is going to give us a mineral sample and we have to identify it.
W: How do you do that? I mean, a rock’s a rock, isn’t it?
M: Actually, there are a lot of tests you can perform on minerals to help you figure out what they are. Probably the first tests I’ll do are scratch tests. When you do a scratch test, you rub the sample on a known mineral to see if the unknown mineral scratches the known mineral or vice versa. That tells you the relative hardness of the sample.
W: What other tests will you do?
M: I’ll probably do a streak test next. In that test, you rub an unknown mineral against a piece of china to see what color the streak is.
W: Why can’t you just look at the mineral to see what color it is?
M: Well, you can, but sometimes a mineral has some other substance in it, and the substance can change its color. But a streak test shows the mineral’s true color. Then there’s always the specific gravity test, the blowpipe test...oh, and...
W: And after you’ve done all these tests, you can positively identify any mineral?
M: Well, usually...but not always. I just hope I can on Monday!
选项
A、They are never effective.
B、They are simple to perform.
C、They are not always very easy.
D、They are usually valid.
答案
B
解析
What does the man imply about the tests used to identify minerals?
转载请注明原文地址:http://tihaiku.com/zcyy/3445813.html
相关试题推荐
[originaltext]CamerooninWestAfricaisanationof(32)24separatelanguag
[originaltext]CamerooninWestAfricaisanationof(32)24separatelanguag
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyou’
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyou’
[originaltext]Joeisastudentatacollegeinanopenarea.Duringhisfir
[originaltext]Joeisastudentatacollegeinanopenarea.Duringhisfir
HowdoesthespeakerfeelaboutTokyo?[br][originaltext]Tokyoisoneoft
HowdoesthespeakerfeelaboutTokyo?[originaltext]Tokyoisoneofthosep
[originaltext]Myfriend,EmmaDaniels,spentthesummerof1974travelingi
[originaltext]Myfriend,EmmaDaniels,spentthesummerof1974travelingi
随机试题
A.financeB.howC.sorrowsD.numberE.clarity
Paperisdifferentfromotherwasteproducebecauseitcomesfromasustaina
[originaltext]Iwillletyouknowthatthere’sabigdifferencebetweenund
AtomicPowersStationsoutatSeaMayBeBetterthanInlandOnes[A]Af
Mancannotgoonincreasinghisnumberatthepresentrate.Inthenext30y
以下关于湿式冷却塔类型及其构造的叙述中,哪项正确?( )A.自然通风湿式冷却塔
选择培养基要选择融合的A.细胞多聚体 B.脾细胞与脾细胞 C.单倍体细胞
A.抗体融合蛋白B.双特异性抗体C.人源化抗体D.小分子抗体E.抗体库技术可在原
药物在体内的代谢和排泄过程统称为A.首过效应 B.肝肠循环 C.转运 D
对患者危害最大的肾损伤是A、肾部分裂伤 B、肾全层裂伤 C、肾盂、输尿管裂伤
最新回复
(
0
)