单词：on again
易变化的；不肯定的
on again的用法和样例：
例句
- Jane doesn't know if she's going to the picnic. She's off again, on again about it.简不知道自己是不是要去参加野餐，她一会儿这样，一会儿那样。
- He took off his large spectacles, gave them a wipe, and put them on again.他把大眼镜摘下来，揩一揩，又戴了上去。
- Has he been trying it on again? I hope you took no notice.他是不是又在耍花招？我希望你没搭理他。
- We were without electricity for three hours but it's on again now.我们的电停了三小时，现在又有了。