什么是核素、同位素和同质异能素？

迷走神经背核属于（）

A．一般躯体运动柱

B．一般躯体感觉柱

C．一般内脏运动柱

D．特殊躯体感觉柱

E．特殊内脏运动柱

某高速公路M合同段(K17+300～K27+300)，主要为路基土石方工程，本地区岩层构成为泥岩、砂岩互层，抗压强度20MPa左右，地表土覆盖层较薄。在招标文件中，工程量清单列有挖方2400000m³(土石比例为6:4)，填方249000m³，填方路段填料由挖方路段调运，考虑到部分工程量无法准确确定，因此采用单价合同，由监理工程师与承包人共同计量，土石开挖综合单价为16元/m³，施工过程中的部分事件摘要如下。
事件1：施工单位开挖路基后，发现挖方土石比例与设计文件出入较大，施工单位以书面形式提出设计变更，后经业主、监理、设计与施工单位现场勘察、洽商，设计单位将土石比例调整为3.4:6.6，变更后的土石方开挖综合单价调整为19元/m³，经测算，变更后的项目总价未超过初步设计批准的概算。
事件2：在填筑路堤时，施工单位采用土石混合分层铺筑，局部路段因地形复杂而采用竖向填筑法施工，并用平地机整平每一层，最大层厚40cm，填至接近路床底面标高时，改用土方填筑。
事件3：该路堤施工中，严格质量检验，实测了压实度、弯沉值、纵断高程、中线偏位、宽度、横坡和边坡。
[问题]

《公路工程设计变更管理办法》将设计变更分为哪几种事件1中的设计变更属于哪一种说明理由。

热轧机组中的热卷箱设备的主要作用是（）。

A．减小带坯的头尾温差

B．存料、便于机组连续化生产

C．便于开卷轧制

A kindergarten teacher decided to let her class play a game. The teacher told each child in the class to bring along a plastic bag containing a few potatoes. Each potato will be given a name of a person that the child hates, so the number of potatoes that a child will put in his/her plastic bag will depend on the number of people he/she cannot forgive（宽恕）.

So when the day came, every child brought some potatoes with the name of the people he/she hated. Some had 2 potatoes; some 3, while some had up to 5 potatoes.

The teacher then told the children to carry the potatoes with them wherever they go (even to the toilet) for one week. With days passing by, the children started to complain because of the unpleasant smell let out by the rotten (腐烂) potatoes they were carrying.

Those children who have 5 potatoes really began to feel the weight of the heavier bags. After one week, the children were happy to hear that the teacher had finally ended the game. The teacher asked: "How did you feel while carrying the potatoes with you for one week?" The children started complaining of the trouble that they had to carry the heavy and smelly potatoes wherever they go.

Then the teacher told them the hidden meaning behind the game. The teacher said: "This is exactly the situation when you carry your hatred（仇恨）for somebody inside your heart. The burden（负担）of hatred will pollute your heart and you will end up carrying an unnecessary burden with you wherever you go.

If you cannot tolerate the smell of rotten potatoes for just one week, can you imagine what a burden it would be to have the hatred in your heart for your lifetime?"

小题1:According to the teacher, if a Child hates three persons, he or she needs to carry ________.

A．one potato

B．two potatoes

C．three potatoes

D．four potatoes小题2:The underlined word “tolerate ” in the last paragraph probably means _____________.

A．carry

B．hate

C．receive

D．stand小题3:In fact, the teacher wants to ______________.

A．play a game with the students

B．teach the students a lesson

C．make the students more tired

D．play jokes on the students小题4:What is the main idea of the story?

A．It’s best to learn to forgive and forget.

B．Students should love people around them.

C．Children should carry less rotten potatoes.

D．Rotten potatoes are really a heavy burden.

β-折叠是（）

A.一级结构

B.二级结构

C.三级结构

D.四级结构

E.结构域