at great speed以很快的速度。通常用的有:at full speed,at high speed
2.When it attempts to leave, the cat finds it cannot move.
attempt to企图,试图
例句:Henry attempted to secure the succession to the office.
亨利试图继承这个职位。
3.This area turned out to be very rich in fossils.
turn out to be结果是, 原来是, 证明是
例句:It turned out to be a wild-goose chase.
结果证明这只不过是一场徒劳。