Many people can’t learn any lessons from the mistakes they’ve made ________ they get hurt somehow.
.____is known to us is that China has won five gold medals in the 2010 Winter Olympic Games.
Medicine should be placed ____children's reach to make sure of safety.
.—I finished all my work today. —If____, you can help others with their work.
I would rather you ____with us yesterday, but you left.
.There has been a(n)____of sadness in the small town since a boy was drowned in the river.