Each person at the reunion was required to talk to other relatives to find out if they would buy one of the histories _______ it were printed A. whether B. if C. when D. after
参考答案:
【考查知识点:微分方程的阶】以下微分方程阶数最高的是()选择一项 a. xy"+y-5xy.=sin
【考查知识点:微分方程的阶】以下微分方程阶数最高的是()选择一项 a. xy"+y-5xy.=sinx b.(y..)+3(y.)4-y5+6x8=0 c.x2