I've been noticing some pain in my chest lately. I should really go get that checked.

最近我发现胸口有点痛。我真应该去检查一下。

Noticing things is only a trouble.

注意到一些事情只是个麻烦。

Mary could not help noticing what strange eyes he had.

玛丽不禁注意到他那双奇怪的眼睛。

She was not used to thanking people or noticing that they did things for her.

她不习惯道谢，也不习惯注意别人为她做事。

Without noticing what I was doing, I took hold of the knob, and open comes the door!

我没有注意到我在做什么，我抓住门把手，门开了！

I couldn't help noticing (that) she was wearing a wig.

我一眼就看出她戴着假发。