当溶解性总固体1000mg/L时，应采用什么温度烘烤。在此温度下，矿物质中含有的吸着

发布时间：2017-10-10 02:09 │ 来源：www.tikuol.com

题型：单项选择题

问题：

当溶解性总固体1000mg/L时，应采用什么温度烘烤。在此温度下，矿物质中含有的吸着水都可除去，重碳酸盐均转变为碳酸盐，部分碳酸盐可能分解为氧化物及碱式盐（）。

A．100±5℃

B．100±2℃

C．110±2℃

D．180±3℃

E．105±3℃

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题型：单项选择题

阅读理解。

Some students are talking about open-book exam:

May:
We students have so many burdens (负担). Maybe examination is the greatest one.
Open-book exams can make our burdens lighter, I think. At least it means that we
need not learn so many things by heart any more.

Hill:
Open-book exams do not mean students do not need textbooks any more. Instead,
it shows how much students really understand about the book. It may mean we
need spend even more time learning history and politics because the open-book
exam means going deeply into the textbooks.

Sun:
We need a long time learning for history and politics exams because there are so
many things to remember. And sometimes the results are not very good, even if we
have spent a long time studying. If we are able to take books into our exams, we
will save time and we won't have so many headaches.

Tang (teacher):
Open-book tests are harder for students because the tests make them feel they do
not need to understand the textbooks any longer. They rely on (依靠) the books
and spend most of their time looking for answers during exams. Sometimes they
might not even be able to finish their tests because they have wasted too much time
looking for answers.

1. Who think open-book exam is easier for students?

A. May and Sun
B. May and Tang
C. Sun and Hill
D. Tang and Hill

2. According to the passage today students ________.

A. like to learn history and politics by heart.
B. have so many burdens.
C. are healthy enough to remember all the things.
D. are not very clever, so they need open-book exams

3. What does Tang think makes some students not be able to finish their tests in time?

A. They can't do it at all.
B. The time for tests is too short.
C. They waste time learning the answers by heart.
D. They don't understand the textbooks very well.

4. Hill thinks that open-book exam means "________".

A. students do not need to read textbooks any more
B. students will save time and they won't have so many headaches
C. how much students really understand about book
D. students need not learn so many things by heart any more

5. According to the text, which do you think is NOT true?

A. You can take your textbook with you in an open-book exam
B. You need to learn more things in the history and politics books by heart in an open-book exam
C. The open-book exam may mean going deeply into the textbook.
D. It has two sides to have an open-book exam — good and bad.

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