（）决定着矿粒按密度分层的效果。
A..水
B.风
C.大气压
D.床层运动状态
参考答案：D
English __________ in our school for almost 60 years.
A．has taught
B．was taught
C．had been taught
D．has been taught
毛果芸香碱可治疗
A．青光眼B．阵发性室上性心动过速C．有机磷酸酯类中毒D．琥珀胆碱过量中毒E．房室传导阻滞
