大海龟今年五百岁,小海龟今年220岁,小海龟多少岁时大海龟的年龄是小海龟的3倍

以蓝鲸、座头鲸等须鲸类为例,它们都是滤食性的,成年海龟估计无法通过他们起过滤作用的须状的牙齿.
以虎鲸等齿鲸类为例,它们作为捕食者,会主动选择攻击的猎物.估计不会去咬成年的海龟,否则的话就是有能力把龟甲咬碎.
其实生态学上来说,海龟一旦成年后,死亡率还是很低的.目前最大的死因还是人类外海捕鱼的时候,被缠在渔网上绕死.

What happened to the big turtle?there are no so many left.

2年前,现在大海龟18,小海龟4岁.

先采后讲

设小海龟X岁,则大海龟3X+15岁
2X-(3X+15)=10
X=5
所以小海龟5岁,大海龟30岁

1,The Egyptian culture is one of the oldest culture in the world.
2There is not any other man-made buildings longer than the Great Wall.
3,What have happened to the sea turtles?It doesn't leave much
4The soldiers efforts to save people and try to use sandbags to stop the ground water level from rising.
5,The longer time the people wait for being help,more dangerous the situation will be
6,How many people died in the flood?
7,How much I ate is twice more than yours
8,The turtles move in the speed of 0.5km/h
9,What is the second longest river in China?
10,What is the population of China?

Today I went to sea world,there was a fierce big shark,the sea turtle,various hanhou of coral reefs,conch,seashells.Thousands of species,such shapes,gorgeous colour of Marine biology."Mermaid performance.

这道题可以用方程,不过我认为用算数方法更简洁.方程就像一楼所写.
算术方法：大海龟今年500岁儿子今年220岁,所以无论何时,大小海龟的年龄差都一定是500-220=280.现在有某一年,大海龟是小海龟年龄的3倍,即大海龟比小海龟大2倍即大280岁.所以1倍就是280/2=140.这就是小海龟的年龄.综合列式就是：
（500-220）/（3-1）=140

①（1）【括号里加标点】片段加标点：可是,到大海龟身边一看,它正在哭呢!眼泪流了一大片.小猴子忙问（：“ ）大海龟（ ,）你为什么哭呀（?）是生蛋太难受（ ”）
（2）（ “）那为什么哭呢（ ）你是不是有什么伤心事（ ”）
②加题目【大概内容】：大海龟的眼泪