I’m afraid I haven’t got a very good ________ of direction. I always get lost in the city.

Those who don’t get their sufficient sleep are actually sending a(n) _____ to severe problems in their life.

The environmentalists said wild goats’ __________ on the vast grasslands was a good indication of the better environment.

They sold their house for only 12,000 dollars, so the buyer got a wonderful ______.

I listened to Dr.Wilson’s lecture about the protection of wild animals,but I was unable to grasp its key _________.