If someone has to     an action or policy, they are responsible for it, and may be  required to explain it to other people or be punished if it fails．

One way to       species under' threat of extinction - whatever the cause - is to remove them to zoos and parks and breed them there．

Having heard wolves howling in the forest, Lala       her walk up the path to the caves fearing that there might be wild beasts lying in wait for her．

When he realized the police had seen him, the man ______ the exit as quickly as possible.

Without my glasses, I couldn’t _____ whether that figure on the blackboard was a three or an eight.

I was so excited at the news that I could hardly _____ my feelings in words.

How do you _______it and what should you ________it?

We tried to _________his doubts and let him tell the truth.

Please tell me how the accident_____. I am still in the dark.