His idea of having weekly family meals together,which seemed difficult at first,has _______ many good changes in their lives.

We ________ get up early and we have a lot of time.

Kangkang, has your homework been finished yet–Yes, mom. I __________ it half an hour ago.

The computer system suddenly while he was searching for information on the Internet.

Nobody knows the man killed in the accident, so it is difficult for the police to find out his _______ .