A startled armadillo jumps straight into the air with an initial velocity of 18 feet persecond. After how many seconds does it land on the ground?
一只受惊的犰狳以18英尺每秒的速度跳向空中。请问它要花多长时间才能落地？
学生：
Armadillo don't jump.
蒙我呢吧，犰狳根本不会跳嘛~
老师居然又回帖了：
not drawing class
这不是美术课= =。