国家基本药物的品种数约占现有品种的（） A.10%～15% B.20%～25%

设备工程设计合同履行中须变更设计方案的，应由( )具体实施。

A．业主

B．监理单位

C．委托方

D．设计方

通信线路维护方式有哪几种？

In a world as fast-changing and full of information as our own, all of us need to know how to learn well. Yet evidence suggests that most of us don’t use the learning techniques that science has proved the most effective.

The scientific literature evaluating these techniques goes back to decades and across thousands of articles. It’s far too extensive and complex for the average parent, teacher or employer to look through. Fortunately, a team of five leading psychologists have done the job for us.

Professor John Dunlosky and other psychologists closely examined 10 learning strategies and rated each from high to low utility(实用) on the basis of the evidence they’ve gathered. Here’s part of their conclusions:

In contrast to familiar practices, the effective learning strategies with the most evidence to support them aren’t well known outside the lab. Take distributed practice, for example. This strategy involves spreading out your study time, rather than engaging in one marathon. Cramming (死记硬背）information at the last minute may allow you to get through that test or meeting, but the material will quickly disappear from your memory. It’s much more effective to look through the material at intervals over time.

And the longer you want to remember the information, whether it’s two weeks or two years, the longer the intervals should be.

The second learning strategy that is highly recommended by Dunlosky is practice testing. Yes, more tests---but there not for a grade. Research shows that the mere act of calling information to mind strengthens that knowledge and aids in future retrieval (检索). While practice testing is not a common strategy---despite the strong evidence supporting it ---there is one familiar approach that captures its benefits: using flash cards. And now flash cards can be presented in digital form. Both distributed practice and practice testing were rated as having “high utility” by Dunlosky.

小题1:How did the psychologists study and rate the learning strategies?

A．By analyzing the materials gathered in the past years.

B．By asking some students questions about their study.

C．By doing some experiments on the objects in the lab.

D．By asking parents and teachers to look through the articles.小题2:The underlined word “extensive” in Para.2 means _____.

A．small in amount

B．easy or quick to do

C．more than is needed

D．dealing with a lot of information小题3:About distributed practice and practice testing, it’s true that _____.

A．many students have benefited a lot from them

B．they were first put forward by John Dunlosky

C．only a small number of experts know about them

D．psychologists are studying whether they are effective小题4:The strategy of distributed practice shows that ______.

A．we should not study for long hours every day

B．reviewing what we have studied is of little help

C．the shorter the interval is, the better we’ll study

D．doing repetition at intervals is the best way小题5:The evidence shows that the strategy of practice testing ______.

A．is a way to use flash cards to help study

B．is mainly used to help us remember well

C．helps know about students’ grades in time

D．is a way widely used to strengthen memory

“验证力的平行四边形定则”的实验情况如图甲所示，其中A为固定橡皮筋的图钉，O为橡皮筋与细绳的结点，OB和OC为细绳。图乙是在白纸上根据实验结果画出的图。

(1)图乙中的___________是力F₁和F₂的合力的理论值；___________是力F₁和F₂的合力的实际测量值。

(2)在实验中，如果将细绳也换成橡皮筋，那么实验结果是否会发生变化？答：___________（选填 “变”或“不变”）。

(3)本实验采用的科学方法是___________。

A．理想实验法

B．等效替代法

下列有关胶剂灭菌的叙述，正确的是（）

A.热压灭菌

B.流通蒸汽灭菌

C.高温高压灭菌

D.包装后紫外线灭菌

E.在紫外线灭菌车间包装