Jbut he ________ careful enough.

It was in Beijing _______Chinese President Xi JinPing held a 4-hour meeting with U.S. Vice President Joe Biden on December 5, 2013.

Generally speaking, light ___ faster than sound. — Yes, it is a rule.

Jane’s dad is getting old, so she has go back home to see him ______ it’s convenient.

ou get a ticket— No, ______, but there wasn’t any left