— The memory pillow cost me a lot of money.
— Did it? Well, that doesn’t matter ___ it helps you relax and have a good sleep.

I was ________ by the salesman whose products turned out to be much less effective.

Our teachers often ask us ______ over the answers carefully before handing in our papers.

At the railway station, the mother waved goodbye to her daughter until the train was _______.

Alexander tried to get his work _______in the medical circles.

-- I heard a student killed his mother cruelly.
-- So did I. It has ____ a serious problem about the education system in China.

I can’t stand ____ with Jane in the same office. She just refuses ____ talking while
she works.

Plants _________carbon dioxide and at the same time _________oxygen. So we may put some in our bedrooms to purify the air.

Smile when ______ the phone. The caller will hear it in your voice.