4．The exact origin of baseball is unknown，but it is probably ____________ an old English game called rounders.
棒球的确切起源是无人知晓的，但是它可能是以英国的一项古老的比赛圆场棒球为基础的。
答案：based on
5．But St Mary had ____________ a captain who was not a typical basketball player.
但圣·玛丽任命的队长是非专业的篮球选手。
答案：appointed
