All flights______ because of the air traffic control, the passengers had to wait in the hall.
–Why has Tom looked unhappy recently? –He has some difficulty ______ with his new classmates at school.
As a scientist, Madam Curie devoted herself ________ to her research and that was why she was given two Nobel Prizes.
She __________ the new laptop which she bought for her brother on the table and went out for supper.
Playing basketball is a sport _________ working as a team matters more.
Actually it was the passenger ________ the driver that caused the serious accident on the road.