诊查“虚里”主候气之盛衰的是
A、宗气
B、营气
C、卫气
D、肺气

单项选择题The expression 'if they can afford to retire' in paragraph 4 probably means______.A.if they are willing to retireB.if they can well support themselves after retirementC.if they are forced to retireD.if they are permitted not to retire

单项选择题你是如何看待实验室安全事故的？