feel|feels|felt

我觉得我应该做更多来帮助她。

I ___feel that I should be doing more to help her.

我确信我是对的。

I ___feel certain I'm right.

他确信那是他的朋友。

He ___felt sure that it was his friend.

我摸了摸他的头，很烫。

I ___felt his head and it was hot.

当她帮助别人时，她感到快乐。

She ___feels happy when she helps others.