题目

阅读理解 Medicine is the most noble of all the arts, but owing to theignorance of those who practice it, and those who inconsiderately form a judgmentof them, it is now far behind all the other arts. Their mistake appears to meto arise principally from the fact that there is no punishment for the practiceof medicine except disgrace, and that does not hurt those who are familiar withit. Such persons are like the figures introduced in tragedies, for as they havethe shape, and dress, and appearance of an actor, but are not actors, so alsophysicians are many in title but very few in reality. W如图所示，一个光滑的小球，放置在墙壁和斜木板之间，当斜木板和竖直 墙壁的夹角θ角缓慢增大时（θ＜90°），则（ ）A．墙壁受到的压力减小，木板受到的压力减小B．墙壁受到的压力增大，木板受到的压力减小C．墙壁受到的压力增大，木板受到的压力增大D．墙壁受到的压力减小，木板受到的压力增大