酒精灯的火焰太小时,将灯芯拨得松散一些,可能火焰更旺,其原理是 [ ] A.降低

题型:选择题

问题:

酒精灯的火焰太小时,将灯芯拨得松散一些,可能火焰更旺,其原理是 [ ]

A.降低可燃物的着火点

B.提高可燃物的着火点

C.增加空气中氧气含量

D.增大可燃物与空气的接触面

考点:燃烧与燃烧的条件
题型:选择题

若a+b<0,ab<0,则下列说法正确的是[ ]

A.a、b同号

B.a、b异号且负数的绝对值较大

C.a、b异号且正数的绝对值较大

D.以上均有可能

题型:选择题

下面短文的画线部分是错误的,请改正,并将其正确答案写在短文后面相应题号后的横线上。

  John was a rich 1.America man. One day he went into a shop when he was

spending his holiday in London. He wanted very much to buy a nice-looking

watch, but the owner of the shop asked five hundred dollars for it. Suddenly a

young man came into the shop, took the watch out of the 2. owner hands and ran

out with it. It all happened in a few seconds. When the owner ran out into the

street, the young man was already 3. losing among the people. John went on. At

the next corner, he saw the young man with the robbed watch in his hand.“Do you

want to buy a fine watch, sir?” he asked in a low voice. “It’s only a hundred

dollars.” “The young man doesn’t know I saw him 4.robbed the watch,” he

thought. John paid for the watch at once and went back to his hotel with the

watch. He told his friend Bill about the fine watch. Bill took a look at the watch

and started laughing. He said, “You are a fool. This watch isn’t worth even ten

dollars. I’m sure the shop owner and the young man 5.planed this together.”

1.________ 2.________ 3.________ 4.________ 5.________

题型:选择题

男,20岁,误服烧碱2小时,急救处理程序中,错误的是()。

A.简要采集病史

B.保持呼吸道通畅

C.尽快建立静脉通道

D.早期使用肾上腺皮质激素

E.食管镜下探条扩张术

题型:选择题

下列选项中属于扩建项目的有______。

A.在恢复的同时进行扩建的项目

B.迁建项目中符合扩建条件的项目

C.为扩大原有产品生产效益而新建的车间

D.为增加新产品的生产能力而新建的项目

E.在原有很小的基础上扩大建设规模,新增固定资产价值超过原有固定资产价值三倍以上的项目

题型:选择题

以下哪个会对电子信息构成威胁?()

A、未授权访问

B、拒绝服务

C、未授权的信息改动

D、以上所有都会危及信息安全

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