The rich or rich people?????

We need to take care old people.  也可以写成We need to take the old.

在英语, old  people 可 缩短至 the old,   those who need help 也可写着  those needy

This charity campaign is to raise fund for old people especially those who are sick.

上面的句子，可改着：

This charity campaign is to raise fund the old especially the sick.

句子的更改，意思还是不变！

Rich people must come forward to help.   Rich people must help poor people.

改后，就如下例的句子

The rich must come forward to help. The rich must help the poor.

上面的缩短词，其用意只是不再重复people