鲁迅在《灯下漫笔》中所指的“第三样时代”的含义是什么?

北京和呼和浩特相距660千米. 一列火车从呼和浩特开出，每时行驶48千米; 另一列火车从北京开出，每时行驶72千米.两列火车同时开出，相向而行，经过几时相遇?两车相遇时，从北京开出的火车比从呼和浩特开出的火车多行了多少千米?

《爱尔克的灯光》一文中，三种灯光分别象征着什么?

用边长30厘米的正方形地砖铺一段长12米，宽6米的人行道路面.

①至少需要多少块这样的地砖?

②如果地砖每平方米的售价是35元，那么购买地砖至少应花多少元?

《宝玉挨打》一文中，宝玉挨打的导火索是什么?根本原因是什么?

五(1)班有学生50人，其中有女生21人，男生占全班人数的几分之几?

“Early to bed ，early to rise ”makes a man healthy, wealthy and wise.It's good for the body.This is an old saying . Have you heard of it before? It means that we must go to bed early at night，and get up early in the morning.Then we shall be healthy.We shall also be rich and clever.That is true .The body must have enough sleep to be healthy.Children of young age should haveenough sleep ，or they can't do their work very well. They will not be wise and they may not become。wealthy! .The body also needs exercise: walking, running, jumping, swimming, playing games and all other。exercise .Exercise keeps the body strong. Exercise also helps the blood to move around inside the.body .This is very important.Our blood takes food to all parts of our body.The head also needs.blood .Exercise helps us to think better.

根据短文内容 ，回答问题.

1.What does “early to bed .early to rise ”mean?

2.What must the body have to be healthy?

3.What will happen to Children of young age who don't have enough sleep?

4.What keeps the body strong?

5.What takes food to all parts of our body?

已知一个梯形的面积是58平方厘米，它的上底是15厘米，下底是25厘米，它的高是多少厘米?

书面表达。

以一种文具为题按要求写一篇英语小作文。

要求：1.要写出此文具的主要特点。

2.条理清楚，意思连贯，标点正确，书写规范 。

3.不少于50个单词 。

简答同时履行抗辩权的成立要件。