Are you going to participatein the speech contest– ____ How wonderful anopportunity!

The town has changed a lot _____ what it was before.

It seems that living green is____ easy and affordable A small step makes a big difference[ ]

It was lucky that little Jack was not at home when the fire broke out；otherwise，hehis life．

ys food safety is a big problem and nobody canguarantee all foods are safe to us, but food produced in the normal companiesis ______ better