【单选题】Mathematica软件中,求解微分方程 的命令为( )。
A.
DSolve[y''+4y'+5y==0,y,x]
B.
DSolve[y''[x]+4y'[x]+5y[x]==0,y[x],x]
C.
Dsolve[y''[x]+4y'[x]+5y[x]==0,y[x],x]
D.
Dsolve[y''+4y'+5y==0,y,x]
【多选题】在肿瘤发生过程中,遗传因素可起重要作用的肿瘤有:
【单选题】I can't read tile sign on the door. Please hold ______.
A.
the light a little closer to it
B.
the light to it a little closer
C.
to it the light a little closer
D.
a little closer the light to it
【单选题】Mathematica软件中,求解微分方程 , 的命令为( )。
A.
Dsolve[{y'-1-y^2==0,y-1==0},y,x]
B.
DSolve[{y'[x]-1-y[x]^2==0,y[0]-1==0},y[x],x]
C.
DSolve[{y'-1-y^2==0,y-1==0},y[x],x]
D.
Dsolve[{y'[x]-1-y[x]^2==0,y[0]-1==0},y,x]
【单选题】I can't read the sign on the door. Please hold______.
A.
the light a little closer to it
B.
the light to it a little closer
C.
to it the light a little closer
D.
a little closer the light to it
【简答题】Don't be too willing to to believe! If he intended to give you the job, he would have called you by now.
【简答题】(2011江苏徐州,22,6分)徐州至上海的铁路里程为650km。从徐州乘“G”字头列车A、“D” 字头列车B都可直达上海,已知A车的平均速度为B车的2倍,且行驶的时间比B车少2.5h. (1)设B车的平均速度为x kn/h,根据题意,可列分式方程: ▲ ; (2)求A车的平均速度及行驶时间.
【多选题】在肿瘤发生过程中,遗传因素可起重要作用的肿瘤包括()。
【多选题】在肿瘤发生过程中,遗传因素可起重要作用的肿瘤包括
【简答题】徐州考古的问题听说前几年在徐州出土过汉代水果,见空气后忽然氧化,求详细资料