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
54
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:https://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
下列工作中,属于施工阶段的有()。A.组建项目经理部 B.严格履行合同,协调好
某建设项目工程费用5000万元,工程建设其他费用1000万元,基本预备费率为8%
商品房买卖合同中,对于面积误差处理没约定的,可以按照一定原则来处理。关于面积误差
下列脑性耗盐综合征的治疗原则中,错误的是A.防止水中毒 B.适当补充氯化钠
A.11 B.12 C.13 D.14
用石灰膏配成()砂浆,用于抹灰或砌筑。A、防水 B、保温 C、防腐 D、水
关于次级债务,下列说法中正确的有()。 Ⅰ.次级债务是由银行发行的 Ⅱ.次
A.肺脏B.肝胆管C.肠黏膜静脉D.小肠E.肝脏实质组织日本血吸虫的寄生部位是
关于哌仑西平说法错误的是A.为吡啶并苯二氮类化合物 B.为选择性M胆碱受体拮
下列用于减少肺内残气量、改善呼吸功能的措施,不正确的是A:做腹式呼吸 B:用鼻
最新回复
(
0
)