氟利昂制冷系统中设臵干燥器的主要目的是（）。

A、防止“冰塞”

B、防止产生“液击”

C、去除垃圾

Concern for family values is reducing among younger Japanese as they pursue an inner world of private satisfaction. Data collected by the Japanese government in 1993 show that only 23% of Japanese youth are thinking about supporting their aged parents, in contrast to 63% of young Americans. It appears that many younger-generation Japanese are losing both respect for their parents and a sense of responsibility to the family. Experts attribute the change to Japanese parents’ over-spoiling of their children, material plentifulness, and growing concern for private matters. The shift toward individualism among Japanese is most striking among the very young. According to data provided in 1991, 50% of Japanese youth aged 16 to 19 can be labeled "self-centered", compared with 33% among those aged 25 to 29. To earn the label, the young people responded positively to such ideas as "I would like to make decisions without considering traditional values" and "I don’t want to do anything I can’t enjoy doing".