My father retired in 2008, _____ he has been devoting his time to gardening.
You have to wear a helmet and a life jacket for protection, just ___ you fall into the water. A. in case C. unless C. though D. As
I toured the Great Wall,I was deeply impressed with the beautiful scenery.
He was about to leave the office for home _______someone knocked the door and asked for some help.
If you find yourself ______ no one will help you, please call me.
The government has taken some measures to solve the shortage of water, but it may be some time __ the situation improves.