Last night, your mobile phone was always busy. I couldn’t ______ to you after several attempts. 

 The meeting was put off because we ________ a meeting without John.

In American schools where students are trained to be creative, some Asian students fail to ______ the creativity they’ve developed and take tutoring classes to raise their points on SAT.

--What do you think of his talk on Information Technology? --Oh, excellent. It’s worth ________.

--Do you know when the Chinese custom_________ from? --It's hard to say. But its characteristics__________ the Tang Period.