Most whales must come up for air after several minutes, _______ a few can stay under water for an hour or more

If you _____ your hand as far as you can, you should be able to touch it.

It was on a train _____ I was travlling to Xi’an _____I made the acquaintance of the old professor from UK.

The ______ of living areas makes wild animals becomefewer than before

Jack is a common person, _______, I think, that will be found everywhere