It is usually not quite cold in this area in March, but sometimes temperature ____be very low.

---- The woman biologist stayed in Africa studying wild animals for 13 years before she returned.---- Oh, dear! She _______ a lot of difficulties!

 I request that you __________ the task on time.

If the weather had been better, we could have had a football match. Bit it ____ all day.

It’s a pity that Andrew didn’t want to go to the conference.________ willing to go，we could have paid all his expenses.