这门课的主要目的是提高英语会话能力。The primary aim of this course is to improve your spoken English.她太轻率了, 她应该学会话出口前想一想.She's too hasty; she should learn to think before speaking.我由于不熟悉英语会话而处于不利地位.I am at an unfavourable position in...
I have patients who are HIV-positive and asymptomatic.我的一些病人艾滋病病毒检测呈阳性，但却无任何体征。His estimate of half a million HIV positive cases was based on an extrapolation of the known incidence of the virus.他估计有50万个HIV阳性病例，这是根据已知的病毒...