He didn't expect that his parents could manage to know ________ is going on in his college life on the Internet.

Don’t stand by when you come across________ have difficulty in supporting their family because of serious illness.

Remember to give me a call ______ you arrive in Beijing.

Aunt Wu is all right ______ her bigger feet.

She had golden hair when she was a child, but_________ she got older and older, her hair went darker and darker.