单项选择题
A．Our interpersonal relationships improve B．Our work efficiency increases greatly. C．Our living habits are altered D．Our behavior is changed
A．Reading a newspaper column B．Looking at a railway timetable C．Driving form New York to Boston D．Waiting for someone at the airport
A．Each flock of butterflies lays eggs in the same states. B．They start to lay eggs when they are nine months old. C．Each generation in a cycle lays eggs at a different place. D．Only the strongest can reach their destination to lay eggs.