_______ the paintings of da Vinci, the Louvre Museum has more than 6,000 other European paintings, _______ from the 13th century to the 19th century.
---Dad, can you tell me why so many students choose to study abroad at a very young age? ---________, darling. I haven never thought about it.
It was ___ the quality of life in the future ___ I took this training course, not just to make more money.
With a lot of difficult problems _, the manager felt like a cat on hot bricks.
Mr Black has two sons, one of ________working as a doctor.
—Who is the man ______ by a group of students there? —A professor _____ research on physics.