How do you say

Kindergarteners can dress themselves now.

..in Chinese?

幼儿班的小朋友现在已经能够自己穿衣服了。

yòu ér bān de xiǎo péng yǒu xiàn zài yǐ jīng néng gòu zì jǐ chuān yī fú le 。

How do you say "He worked out in the gym for three months and gained a lot of muscles." in Chinese?