①木炭是灰黑色的多孔性固体；②木炭能燃烧；③我国某些地方冬天_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

①木炭是灰黑色的多孔性固体；②木炭能燃烧；③我国某些地方冬天有时用木炭来取暖；④将木炭粉碎；⑤木炭可制黑火药；⑥取一小块木炭点燃，放入氧气瓶中燃烧，发出白光．上述描述属于物理性质的是______（填序号，下同），属于物理变化的是______，属于化学性质的是______，属于化学变化的是______，属于用途的是______．

答案

①木炭是灰黑色的多孔性固体，描述的是碳单质的物理性质；

②木炭能燃烧，描述的是碳单质的化学性质；

④将木炭粉碎，没有新物质生成，描述的是木炭物理变化；

⑥取一小块木炭点燃，放入氧气瓶中燃烧，发出白光，描述的是木炭在燃烧过程中的现象，是化学变化．

③我国某些地方冬天有时用木炭来取暖；⑤木炭可制黑火药；描述的是木炭的用途．

故答案为：①，④，②，⑥，③⑤．

阅读理解

阅读下列语段，并将它们重新排列顺序，组成一篇连贯的短文。

A. The shorter boy replied, “When someone hurts you, you should write it in the sand from which the wind can erase it easily. However, when someone does something good for you, you should carve( 雕刻) it on a stone from which the wind can never erase it.”

B. The taller boy asked him, “After I hurt you, you wrote in the sand, but now you carve on the stone. Why?”

C. Two friends were walking through the desert (沙漠). During the journey they had an argument, and the taller boy hit the shorter one in the face. The shorter boy was hurt.

D. They kept on walking until they found a pond (池塘). And they decided to take a bath there. The shorter boy got stuck in the mud and started to sink, but luckily he was saved by the taller boy. After that, he carved on a stone, “Today my best friend saved my life.”

E. But without saying anything, he wrote in the sand, “Today my best friend hit me in the face.”

The right order:1. 2. 3. 4. 5

多项选择题简答题

造成地震电缆线工作电容增大的原因有（）。

A、电缆绝缘层厚度增大

B、电缆绝缘层厚度减小

C、电缆绝缘层受潮

D、电缆绝缘层受到日嗮