We all know about the_____ that smoking can do to our health.

Too many people are indifferent _______others ‘ troubles.

The rediscovery of this species of birds is one of the most___(ordinary)scientific findings in recent years.

I _____him 150 dollars and must pay him back tomorrow.

Ifyouhavetheright___(equip)，youwon’tfindthejobdifficult.