The main point of paragraph 4 is ______.
A. why geriatric physicians are paid less than other physicians
B. why doctors show little interest in being geriatric physicians
C. what are the major problems with the elderly care industry
D. what can be done to ensure the healthy development of elderly care
【B1】
A. thing
B. school
C. homework
使用FTP传送任何类型的文件，在进行文件传送时，FIT客户机和服务器之间要建立两个连接：控制连接和——。
A. 网络连接
B. UDP连接
C. 数据连接
D. IP连接
Umbrellas were firstly used to keep people from ______.
A. sun
B. rain
C. animals
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