【判断题】课堂教学是实现人才培养目标的主要途径。()
【单选题】关于抗原特异性的描述,正确的是:
D.
两种天然抗原物质之间也可以表现出相同的抗原性
【判断题】客户关系管理系统结构可分为界面层、功能层和技术层三部分。
【单选题】The size of the workforce declines when ______.
A.
many people reach the retiring age
B.
the birth rate falls rapidly
C.
the number of retirees exceeds that of new workers
D.
the death rate increases
【单选题】Some people find retiring difficult, but he has taken it all______ .