小华同学在做“探究电磁铁”实验中,用两个相同的大铁钉绕制成电磁铁进行实验,如图所

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问题:

小华同学在做“探究电磁铁”实验中,用两个相同的大铁钉绕制成电磁铁进行实验,如图所示.

①小华同学是通过观察______来确定电磁铁的磁性强弱,由图可知,线圈的匝数越______,电磁铁的磁性越强.

②要使图中电磁铁磁性增强,应将滑动变阻器的滑片向______滑动.

考点:影响电磁铁磁性的因素
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颅颈侧位、张口正位X线平片,测量_________位置是确诊颅底凹陷症的重要依据。超过腭枕线_________mm可确诊。

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社会主义国家的基本特征是什么?

题型:问答题

B

Uncle Li and Uncle Wang are good friends. They live next to each other and their farms are both at the foot of the mountain. So they can help each other. But neither of them likes to use his head. They’re both poor though they work hard. Most villagers have built new houses, but they still live in the low and broken houses. They never find out why.

Once Uncle Li went to the town to buy some medicine for his wife. In the town he heard the apples in a city were expensive. He told Uncle Wang about it as soon as he went back. They decided to carry some apples to the city. They borrowed some money from their friends and bought nearly 1000 kilograms of apples in the villages and carried them to the city on a tractor. Bad luck! A lot of apples has already been carried there when they arrived. A few days later they had to sell them at a low price. They felt unhappy and returned to their village.

"I can’t understand why we sustained (蒙受) losses in business while others always profit (赢利)" Uncle Li asked one day.

"The tractor was too small " Uncle Wang said without thinking. "We’ll carry more apples on a truck next time !"

"I agree!" said Uncle Li. "How foolish we were!\

The two farmers carried the apples to the city to().

A.make a journey

B.visit some places of interest

C.meet their friends

D.make a profit

题型:问答题

关于缺铁性贫血对妊娠的影响,哪项是错误的

A.孕妇易发生感染

B.轻度贫血对妊娠影响不大

C.重度贫血易发生妊娠高血压综合征

D.重度贫血可导致心肌缺血

E.铁可以通过胎盘双向运转,但在一般情况下胎儿摄取占主要优势

题型:问答题

装设木电杆地线,顶端高出电杆()毫米。

A.100~200

B.150~200

C.100~300

D.150~300

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