问题 问答题

如图为在空中飞行的足球,请在图中画出球所受20N重力的图示.

答案

足球在空中飞行是由于惯性的作用,这不会影响到它的重力,它的重力大小依然是20N,方向竖直向下,作用在足球的重心上.如图所示:

多项选择题

某年某月某日,某市某化塑制品厂发生火灾,整个厂房被烧毁,造成直接经济损失达127.6万元。
当日8时上班后,工人孙某在该化塑制品厂压球车间门口西侧用电焊焊接压模。焊接现场的周围除一条3m宽的通道外,堆满了袋装成品浮球及废料,还有数个装丙酮、乙烷的铁桶。8时20分左右,拌料员谷某要在孙某作业处西侧约1.5m左右的地方,从铁桶中抽取丙酮,即告诉孙某要先停止电焊,孙某同意后便离开作业处。谷某用塑料管从铁桶向塑料桶中抽取丙酮,由于操作不当将丙酮洒在水泥地面上,谷某没有采取任何措施就离开了现场。孙某回到作业处,没有检查也没有采取任何防护便继续电焊。在焊接约3cm长的一段接缝时,电焊溅起的火花将洒在地上的丙酮点燃,孙某见起火,用正在焊接的方模去压地上的火苗,但火苗仍然四溅。孙某与另一名工人先后取来3只灭火器,均未启动成功。火借风势迅速蔓延,整个厂区被大火吞噬。直到11时,大火才被扑灭。
事故发生后,该市人民检察院受理了此案,这起火灾事故是由于违章堆放危险品,遇明火而引起的,谷某等4人对此负有责任。经现场勘察和调查认定,谷某、孙某在生产过程中,违反规章制度,导致发生特大火灾,造成集体财产遭受严重损失,他们的行为触犯了《中华人民共和国刑法》第114条的规定,构成重大责任事故罪。厂领导孙某和厂长刘某身为企业管理人员,不认真履行职责,对厂内事故隐患熟视无睹,对工人的违章作业放任自流,以致由于操作工人在事故隐患区域作业而发生特大火灾,他们的行为触犯了《中华人民共和国刑法》第187条的规定,构成玩忽职守罪。
根据以上场景,回答下列问题(1~3题为单选题,4~8题为多选题,请将正确选项代码填写到题干括号内)

初起火灾扑救的方法是( )。

A.发生火灾后,要及时使用本单位的灭火器材、设备进行扑救

B.有手动灭火系统的应立即启动

C.断绝可燃物

D.采取冷却、窒息、扑打的方法

E.阻止火势蔓延,防止发生爆炸

阅读理解

“When can I get a cell phone?” The answer is when your parents think you need one, though many kids seem to be getting them around age 12 or 13. Some younger kids may have them because their parents see it as a matter of safety and convenience. For example, a kid can call mom and dad when sports practice is over. And a cell phone can give kids almost instant access(快捷通道) to their parents if something goes wrong or they need help. It can give parents quick access to their kids so they can check on them and make sure they’re OK.

If you do get a cell phone, make some rules with your parents, such as how many minutes you’re allowed to spend on the phone, when you can use your phone, when the phone must be turned off, and what you will do if someone calls you too often, and so on.

You’ll also have to learn to take care of the phone in your life. Keep it charged(充电) and store it in the safe place so it doesn’t get lost. And whatever you do, don’t use it in the bathroom. I know someone who dropped her phone in the toilet! 

小题1:Parents buy cell phones for their kids because ___________.

A.they think it is necessary

B.they think their kids are old enough

C.they have asked the author for advice

D.they want to follow their kids wherever they are.小题2:The author of the passage ___________.

A.wants to describe how children use cell phones

B.knows nothing about when children can have a cell phone

C.may have done a survey on kids using cell phones

D.has been a teacher for many years小题3:Which of the following is true?

A.It is too young for kids of 12 or 13 to get a cell phone.

B.A cell phone is useful for kids and their parents.

C.The author is against the idea of kids to have cell phones.

D.Most kids are considering having cell phones.小题4:Who is the passage most probably written by?

A.Parents who have bought phones for their kids.

B.Someone who does cell phone business.

C.A teacher who cares most about school safety.

D.Someone who works for children’s education.小题5: Which might not be a rule for kids with a cell phone?

A.Keep it on all the time.

B.Make a call if something goes wrong.

C.Don’t use it in the bathroom.

D.Take care not to lose it.