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
2023-07-12
35
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/2829546.html
相关试题推荐
[originaltext]CamerooninWestAfricaisanationof(32)24separatelanguag
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyou’
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyou’
[originaltext]Ifyou’vebeenoncampusforverylong,I’mcertainthatyou’
[originaltext]Conversationsarereallykindofinteresting.Iguessit’sa
[originaltext]Joeisastudentatacollegeinanopenarea.Duringhisfir
HowdoesthespeakerfeelaboutTokyo?[br][originaltext]Tokyoisoneoft
HowdoesthespeakerfeelaboutTokyo?[originaltext]Tokyoisoneofthosep
[originaltext]Myfriend,EmmaDaniels,spentthesummerof1974travelingi
[originaltext]Myfriend,EmmaDaniels,spentthesummerof1974travelingi
随机试题
Manstillhasalottolearnaboutthemostpowerfulandcomplexpartofhis
下列关于水喷雾灭火系统的表述中,哪几项正确?()A.水喷雾灭火系统是雨淋系统
要保证两个流动问题的力学相似,下列描述中哪一条是错误的?( )A.流动空间相
A类网络是很大的网络,每个A类网络中可以有( )个网络地址。实际使用中必须把A
急性胆囊炎穿孔的表现形式,下列哪一种最为多见A.形成腹腔脓肿 B.引起弥漫性胆
A.自我试验 B.强迫试验 C.临床试验 D.志愿试验 E.天然试验应用
(2018年真题)基金托管费通常按( )的一定比例提取。A.基金总收益 B.
净稳定资金比例指标包含的内容有( )。A.可用稳定资金 B.存贷比 C.所
A.卵磷脂 B.桂醇硫酸钠 C.聚山梨酯-80 D.新洁尔灭 E.脱水山
职业肿瘤是指A.由职业性致癌因素引起的肿瘤 B.由致癌因素引起的肿瘤 C.由
最新回复
(
0
)