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
28
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、Its relative hardness.
B、Its true color.
C、Its chemical composition.
D、Its relative purity.
答案
B
解析
According to the man,what does a streak test show about a mineral?
转载请注明原文地址:https://tihaiku.com/zcyy/3445812.html
相关试题推荐
[originaltext]CamerooninWestAfricaisanationof(32)24separatelanguag
[originaltext]CamerooninWestAfricaisanationof(32)24separatelanguag
[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
[originaltext]Myfriend,EmmaDaniels,spentthesummerof1974travelingi
随机试题
WelcomeaboardDragonairAirlinesFlight121HongKongtoParis.Ourflight
金融危机、货币宽松与经济增长(请阅读下面关于美国量化宽松的描述并简要回答问题,要
从四个选项中选择最合适的一个填入问号处,使之呈现一定的规律性。( ) A.A
某工业企业,资产总额为2000万元,从业人数80人,2019年取得营业收入25万
说明某现象发生的强度指标为A.全距 B.相对比 C.率 D.均数 E.比
常用于各种阴道炎、宫颈炎、宫颈癌等A.熏洗法 B.坐浴法 C.冲洗法 D.
实施冲击疗法,每次的极限水平的标志是( )。A.求助者气促、出汗 B.求助者受
小张高中毕业之后,去上了四年大学,如果他当时没有上大学,而是去上班,四年下来,他
某年冬季,有一42岁男子,因发热、头痛、眼眶痛、腰痛3天,体温在40~40.6℃
甲施工企业有一辆里程表存在故障的工程用车,该车实际行驶里程8万公里,市场价格约为
最新回复
(
0
)