物理实验中,对于一些不易直接测量的物理量,通常利用相关的物理效应间接比较其大小.

题型:探究题

问题:

物理实验中,对于一些不易直接测量的物理量,通常利用相关的物理效应间接比较其大小.

(1)图1所示是“探究物体动能的大小与什么因素有关”的实验,该实验中“物体动能的大小”是通过 __________ 来反映的;

(2)图2所示是“比较不同燃料热值”的实验,该实验中“燃料燃烧放出热量的多少”是根据 __________ 来比较的;

(3)图3所示是“研究电流做功多少与电压关系”的实验,该实验中“电流做功的多少”是根据 __________ 来比较的.

考点:动能的影响因素热值电功或电能的计算
题型:探究题

下列关于采用预制安装法施工桥梁承载结构,叙述正确的是( )。

A.构件质量好,尺寸精度高

B.桥梁整体性好,但施工费用高

C.不便于上下平行作业,相对安装工期长

D.减少或避免了混凝土的徐变变形

E.设备相互影响大,劳动力利用率低

题型:探究题

Parenting was never a piece of cake in any age, but probably the greatest source of headache for parents today in Japan is the ubiquitous cellphone. Today, 96 percent of senior high school students and 58 percent of junior high school students have cellphones. Even among primary school children, 31 percent have them.

By enabling youngsters to stay connected with their parents at all times, these gadgets help to keep children safe. For the kids, they are fun toys, too, that let them text to or chat with their pals whenever they want, play Internet games, and enjoy blogging for their own profile and diary purposes.

But terrible dangers lurk beneath all that fun and convenience.

Every year about h 000 children become involved in rape and other crimes through dating service sites. Violent and obscene images are only a couple of clicks away. On gakkoura saito, or so-called unofficial school websites where kids can post whatever they want, anyone can fall victim to brutal "verbal mob lynching" by their peers.

Amid today’s urgent need to address these problems, the government’s Meeting on Education Rebuilding has issued a report. In response to the Prime Minister’s recent comments — "I cannot think of one good reason for (letting youngsters) have a cellphone" and "I would like everyone to discuss whether cellphones are really necessary" — the report recommended that "parents, guardians, schools and all parties concerned should cooperate among themselves, so that elementary school pupils and junior high school students do not have a cellphone unless there is a compelling reason for them to do so."

But since many parents believe in the necessity of cellphones as a safety tool, it is unrealistic to expect everyone to do away with them. Rather, it would make more sense for guardians, schools and cellphone companies to consider, from their respective standpoints, how cellphones should be used by children.

We suggest that parents sit down with their offsprings and talk about their "house rules" for cellphone use. For instance, set the hours allowed, so the kids won’t be texting to their friends late into the night, remind them never to give away personal information online, and so on,

But there are limits to what individual families can do, and this is where we also suggest that schools should educate their pupils on the dangers of cellphone use. One way to go about this, for instance, may be for each class to set its own rules on sending e-mail messages.

The report issued by the government’s Meeting on Education Rebuilding().

A.recommended minimizing the use of cellphones among kids

B.suggested setting "house rules" for cellphone use

C.urged parents to .remind their children about cellphone use

D.pressed schools to educate their pupils on the dangers of cellphone use

题型:探究题

焊条横向摆动的目的是为了获得一定宽度的()。

题型:探究题

以下属于反风设施的是()。

A.反风风道

B.防爆盖

C.反风风门

D.反风风门绞车

题型:探究题

测量曲轴臂距差后,应对所测数据依据()进行分析和判断。

A.柴油机说明书

B.具体情况

C.有关标准

D.柴油机说明书和有关标准

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