二尖瓣狭窄
mitral stenosis (physiology)
勤俭办企业
to run an enterprise diligently and thriftily
勤俭办学
to run a school diligently and thriftily
勤俭办社
to run an organization diligently and thriftily
半封建半殖民地
semi-feudal and semi-colonial (the official Marxist description of China in the late Qing and under the Guomindang)