复发性口腔溃疡的病因是（） A.病因不清，多种因素作用 B.细菌感染 C.局部刺激

试论班主任在班级管理中的地位与作用。

You can’t always predict a heavy rain or remember your umbrella. But designer Mikhail Belyaev doesn’t think that forgetting to check the weather forecast before heading out should result in you getting wet. That’s why he created Lampbrella, a lamp post with its own rain sensing umbrella.

The designer says he came up with the idea after watching people get wet on streets in Russia. “Once, I was driving on a central Saint Petersburg street and saw the street lamps lighting up people trying to hide from the rain. I thought it would be appropriate to have a canopy(伞蓬)built into a street lamp,” he said.

The Lampbrella is a standard-looking street lamp fitted with an umbrella canopy. It has a built-in electric motor which can open or close the umbrella on demand. Sensors(传感器)then ensure that the umbrella offers pedestrians (行人) shelter whenever it starts raining.

In addition to the rain sensor, there’s also a 360° motion sensor on the fiberglass street lamp which detects whether anyone is using the Lampbrella. After three minutes of not being used the canopy is closed.

According to the designer, the Lampbrella would move at a relatively low speed, so as not to cause harm to the pedestrians. Besides, it would be grounded to protect from possible lightning strike. Each Lampbrella would offer enough shelter for several people. Being installed at 2 meters off the ground, it would only be a danger for the tallest of pedestrians.

While there are no plans to take Lampbrella into production, Belyaev says he recently introduced his creation to one Moscow Department, and insists this creation could be installed on any street where a lot of people walk but there are no canopies to provide shelter.

小题1:For what purpose did Belyaev create the Lampbrella?

A．To predict a heavy rain.

B．To check the weather forecast.

C．To protect people from the rain.

D．To remind people to take an umbrella.小题2:What do we know from Belyaev’s worlds in Paragraph 2?

A．His creation was inspired by an experience.

B．It rains a lot in the city of Saint Petersburg.

C．Street lamps are protected by canopies.

D．He enjoyed taking walks in the rain.小题3:Which of the following show how the Lampbrella works?

A．motor→canopy→sensors

B．sensors→motor→canopy

C．motor→sensors→canopy

D．canopy→motor→sensors小题4:. What can be inferred from the last paragraph?

A．The designer will open a company to promote his product.

B．The Lampbrella could be put into immediate production.

C．The designer is confident that his creation is practical.

D．The Lampbrella would be put on show in Moscow.

开成公司与浩新物资供应公司于2002年5月1日签订了一份原材料供应合同。双方约定：开成公司于5月15日将货款及运输费用共计55万元汇入浩新公司账户，浩新公司见款立即发货。开成公司按约付款，但浩新公司由于不可抗拒的原因无法按合同约定的数量供货，遂与开成公司进行了交涉并达成协议，即浩新公司按现有数量供货，余款退回。5月20日，浩新公司发出价值30万元的材料(含运输费用)，并退回货款20万元。开成公司见短缺5万元便与浩新公司交涉。浩新公司的解释是，短缺的5万元系开成公司经办此项业务的业务员甲借走，至今未还。双方未达成一致意见，遂诉至法院。经调查，甲曾在签约前以个人名义借去2万元，后又持加盖开成公司公章的空白介绍信借去3万元。在法院的调查过程中，发现开成公司曾于半年前为裕和电器厂向前山投资公司贷款40万元提供担保。该电器厂已于两个月前向法院提出破产申请，法院已发出公告。但前山投资公司并未申报债权。 此外，开成公司为了改制，与大地、清远两企业共同出资创办了一家从事实业的有限责任公司。2002年12月，该公司与乙公司以及美国一家公司磋商拟成立一家合营企业，并按有关法律的规定约定了各方的出资额和出资方式，并委托实业公司办理报批、登记手续。美国公司按照约定日期将出资额汇入了实业公司账户。三方签订了合同，并办理了登记。后发现，实业公司和乙公司一直未按规定日期缴清出资额，实业公司也未将美国公司的出资额转入合营企业账户。美国公司催缴未果，提出终止合同，要求退还出资额并赔偿损失。但美国公司的出资额已被实业公司挪用。美国公司与其交涉未果遂寻求法院支持。此案结束后，大地、清远企业提出终止实业公司，开成公司不同意，于是在董事会上投票表决，9名董事中有5名同意，公司遂成立清算组。 要求：根据以上资料，分析回答下列问题： (1)开成公司业务员甲的借款应由谁负责追还，并说明理由。 (2)开成公司作为裕和电器厂贷款的担保人，在前山投资公司不参加破产程序时，是否可以申请参加破产程序并说明理由。 (3)美国公司先期汇入被挪用的出资额应由谁负责偿还因终止合同而给美国公司造成的损失应由谁负担并说明理由。 (4)实业公司董事会作出的关于终止公司的决议是否有效并说明理由。

二手车价值评估采用哪些方法？

什么叫二次系统？按其性质和用途可分为哪几类？