单项选择题According to the passage, all of the following are advisable to older adults for a fitness program except ______.
单项选择题The word embrace (Sent. 2, Para. 3) may convey the meaning of ______.
单项选择题The author mentions that the maximum THR for older adult participants in sports should he less than ______ beats per minute.
单项选择题According to the author, ______.
单项选择题According to the passage, a private enterprise economy is characterized by ______.