【单选题】清代周济词学著作为《__________》。
【简答题】阅读上面的短文完成句子,每空一词: Why Are You Buying All These Tickets? Why Are You Buying All These Tickets? A small man wants to see a film, so he comes to a cinema. He buys a ticket and goes in. But after two or t...
【单选题】男,65岁。干咳2周入院,无发热、咯血及呼吸困难。查体:心肺未见异常,双手可见杵状指。胸部X线片显示右下肺约3cm的类圆形阴影。其内可见小空洞。首先考虑()
【简答题】Why is it a problem if all the smaller fish species die?
【单选题】男,65岁,干咳2周入院,无发热、咳血及呼吸困难。查体:心肺未见异常,双手可见杵状指。胸部X线片示右下肺可见直径约3cm的类圆形阴影。其内可见小空洞。该患者应首先考虑的诊断是
【简答题】求解下列微分方程: (1)xy'-y[ln(xy)-1]=0 (2) (3)(1+ex)yy'=ex,满足y|x=1=1的特解.求解下列微分方程: 1.xy''=y'ln(y'/x) y=1/C1(x-1/C1)e^(C1x+1)+C2 2.yy''-y'^2=y^2*y' y=C1C2e^(C1x)/(1-C2e^(C1x)) ; y=C2