decide （not）to do sth. 决定（不）做某事
decide +宾语从句 决定……
decide +特殊疑问词+to do 。
It was sunny and hot,so we decided to go to the beach near our hotel.
We decide that we'll try our best to protect the environment.
All these pictures are very beautiful. I haven't decided which to choose.
（2）decide 的名词形式为decision, 意为“决心；决定”，常构成短语make a decision,意为“作出决定”。
Let's have a try.