下列属于动物学习行为的是 [ ]
A.飞蛾扑火
B.母鸡孵卵
C.蜜蜂采蜜
D.老马识途
答案:D
There are more than fifty _________ in our school.
A.woman teachers
B.women teachers
C.women teacher
D.woman teacher
按发行主体的不同,债券可分为( )。
A.政府债券
B.金融债券
C.公司债券
D.贴现债券
E.担保债券