The boy is only four years old, but he can swim ______ the lake.

My father advises me _____ games, he thinks it’s not good for my study.

ations, which are astronomicallyexact, have been madewith the use of computers

15．The book Been There, Done That written by a Chinese Americangraduate is _____a real story.

News came from the office __________ Wang Lin had beenadmitted to Beijing University.