1．It is reported that thirty people were killed in a __collision__(collide) on the railway yesterday.
2．The society today offers the young generation more chances to show __off__ their talent and skills.
3．Mr Collins undertook __to_look__(look) after the children so that his wife could go to the club with two of her friends.
4．In America, presidential __elections__(elect) are held every four years.
5．While __crossing__(cross) the street, he was knocked over by a car.
6．The Great Wall of China __dates__(date) from the Qin Dynasty.
7．We have asked the neighbours to keep __an__ eye on the house for us while we are away.
8．She picked __up__ some Spanish when she was living in Mexico.
9．Lost in thought, he almost knocked __into__ a man who carried a heavy box.
10．I'll leave you __to_undertake__(undertake) an important mission.
