The professor ________at 8 o’clock，but he has not shown up yet，which worries all of us.

he was investigating ways to improve the telescope, Newton made______ discover which completely changed______man’s understanding of colour.

She was working in the room suddenly she heard a boy crying and ________ out as quickly as she could to see what was happening.

Yes, ______ is difficult to find a job nowadays, but _____ is more difficult is try to find such a job with a high salary but little things to do

Thank you for visit to CCTV.COM. Thissite_________and will be back online in the not-too-distant future.