用It's adj to do sth
need to do sth
decide to do sth/decide not to do sth
用It's adj to do sth
need to do sth
decide to do sth/decide not to do sth
It's foolish to go there on foot.
You need to study English well if you want to go abroad.
She decide to go to school by herself.
Is't eay to learn english.
I need do my homework.
I decide play baskteball.
it's difficult to answer these questions
i need to finish the homework this evening
i decide to follow his suggestions/i decide not to follow his suggestions