计算2a-3(a-b)的结果是( ) A.-a-3b B.a-3b C.a+3b

题型:选择题

问题:

计算2a-3(a-b)的结果是(  )

A.-a-3b

B.a-3b

C.a+3b

D.-a+3b

考点:整式的定义整式的加减单项式多项式同类项
题型:选择题

疟疾病人的外周血液检查显示()

A.白细胞总数明显升高

B.血小板增多

C.网织红细胞减少

D.红细胞减少

E.大单核细胞减少

题型:选择题

根据环境污染的来源我们可以把环境污染归纳为二个因素

A.生物因素、化学因素

B.物理因素、化学因素

C.人为的因素和自然的因素

D.直接因素和间接因素

E.工业“三废”和生活因素

题型:选择题

阅读理解。

     Green-space facilities are contributing to an important extent to the quality of the urban environment.

Fortunately it is no longer necessary that every lecture or every book about this subject has to start with

the proof of this idea. At present it is generally accepted, although more as a self-evident statement than

on the base of a closely-reasoned scientific proof. The recognition of the importance of green-space in

the urban environment is a first step on the right way; this does not mean, however, that enough details

are known about the functions of greenspaces in towns and about the way in which the inhabitants (居民)

are using these spaces.

     The theoretical separation of living, working, traffic and recreation which for many years has been

used in town-and-country planning, has in my opinion resulted in disproportionate (不成比例的) attention

for forms of recreation far from home, whereas (但是) there was relatively little attention for improvement

of recreative possibilities in the direct neighborhood of the home. We have come to the conclusion that this

is not right, because an important part of the time which we do not pass in sleeping or working, is used for

activities at and around home. So it is obvious that recreation in the open air has to begin at the street door

of the house. The urban environment has to offer as many recreation activities as possible, and the design

of these has to be such that more obligatory(强制性的) activities can also have a recreative aspect.

     The very best standard of living is nothing if it is not possible to take a pleasant walk in the district, if the

children cannot be allowed to play in the streets, because the risks of traffic are too great, if during shopping

you can nowhere find a spot of enjoying for a moment the nice weather, in short, if you only feel yourself

at home after the street door of your house is closed after you.

1. According to the author, the importance of greenspaces in the urban environment ____.

A. is still unknown

B. is being closely studied

C. is usually neglected

D. has been fully recognized

2. The theoretical separation of living, working, traffic and recreation has led to ____.

A. the disproportion of recreation facilities in the neighborhood

B. all of the recreation facilities far from home

C. relatively little attention for recreative possibilities

D. the improvement of recreative possibilities in the neighborhood

3. The author suggests that the recreative possibilities of greenspaces should be provided ____.

A. in special areas

B. in the suburbs

C. in the neighbourhood of the home

D. in gardens and parks

4. The author says "more obligatory activities can also have a recreative aspect" to ____.

A. suggest that obligatory activities don't need to serious

B. show that recreation activities are very important

C. show how recreation activities have spread wildly

D. suggest how to offer recreation activities around home

5. Why would someone only feel himself at home according to the last paragraph?

A. One lives the very best standard of living.

B. There are too many distractions outside his home.

C. There are few recreations around his house.

D. One needs the street door of his house to be opened always.

题型:选择题

根据KNO3和NaCl的溶解度曲线,回答下列问题:

⑴10℃时KNO3的溶解度_________(填“>”、“<”或“=”)NaCl的溶解度。

⑵t℃时,将mgKNO3、ngNaCl分别溶解在20mL水中恰好饱和,则m____n(填“>”、“<”或“=”)。

⑶工业上采用如下的流程从海水中提取精盐:

上述流程中Ⅰ、Ⅱ、Ⅲ分别是①_________、②________、③___________。

题型:选择题

尸检的肉眼观察包括()

A.体表检查

B.胸、腹腔有无积液,积液的性状

C.各脏器的大小、形态、重量

D.各脏器的表面和切面颜色等

E.上述各项均包括

更多题库