下列属于动物的学习行为的是 [ ]
A.蜜蜂采蜜
B.蜘蛛结网
C.大山雀偷饮牛奶
D.喜鹊筑巢
答案:C
患者,女性,40岁。确诊原发性肺动脉高压5年,平时无明显症状。心脏超声示右心室扩大,肺动脉压力35mmHg。为降低其肺动脉压力,予以血管扩张剂治疗,临床常用的药物是()
A.酚妥拉明(立其丁)
B.硝酸甘油
C.硝苯地平
D.氨氯地平
E.硝普钠
Last year he had an opportunity _____ abroad, but he gave it up. [ ]
A. study
B. to study
C. of study