Calculations，which are astronomically exact，have been made ________ with the use of computers.

Henry speaks Chinese very well. He ______ in China since 2002.

Mr. Black used to be busy. But now he’s retired and , so he has plenty of time to exer cise.

Sometimes people can be too tired to ________

Many people watched CCTV’s Dictation Assembly of Chinese Characters(汉字听写大会). It had a great ____on developing our native language.