For example, did you know that 1 in 4 teenagers has tried marijuana?
比如,你是否知道4个青少年中就有1位曾经吸过大麻?
recorded for the slumbering scientist the strength of a shock that was too weak to waken him,and the direction from which it came.
由于地震太弱而未惊醒科学家时,就为科学家记录下了地震的强度和地震方向。