根据句意和汉语注释，写出单词的正确形式。
Parents should have more ______________ (交流) with their children.
Finally, the climber ______________ (设法完成) to get to the top of the mountain.
The rich man has a lot of poor ______________ (亲戚). He gives them much money every year.
It is amazing that a cow has four ______________ (胃).