.The reason for his success is ______ he worked very hard.
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.
Many developed countries have agreed to help the less developed ones but it remains ________ whether they will take action or not.