【单选题】The opportunity cost of a one-unit increase in an activity
A.
is greater than the marginal benefit.
B.
is called rational cost.
C.
decreases as you do more of it.
D.
is called marginal cost.
E.
is measured by what the person is willing to give up to get one more unit of the activity.
【判断题】理想信念是精神上的钙,没有崇高的理想信念,就会导致精神上的“软骨病”( )
【多选题】以下方法可用于晶硅电池生产刻蚀边缘的是______。
【单选题】The marginal social cost of a unit of pollution:
A.
is the additional cost imposed on society by that unit.
B.
is easy to calculate, since pollution produces costs.
C.
is often overestimated.
D.
remains constant as more of a good is produced.
【单选题】SQL语言中,删除一个表的命令是( )。
【多选题】下列关于睾丸间质细胞的描述,正确的是
B.
细胞体积大,常成群分布在生精小管之间的睾丸间质中
【判断题】理想是精神之钙,没有崇高的理想信念,就会导致精神上的软骨病
【单选题】男性,15岁。双侧阴囊内空虚。B超检查:双侧睾丸下降不全,睾丸位于腹腔内。睾丸的内分泌功能是由睾丸间质细胞和支持细胞完成的,支持细胞的功能不包括