It was not rare(稀少) in that people in fifties were going to school for further study.
Actually,the London Olympic Park is built _____________ there used to be a poor area called East London.
I find that looking after children is a fun and challenging job ___________ you need to be patient and careful.
___________ we can have clean drinking water lies in ___________ effective measures will be taken by the government about water pollution.
There are many new central leaders in China now, ________ many once worked in the western provinces.
Both students and parents appreciate the great importance schools have ______to eyesight protection.