【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】What does “door closer” in the title mean?
B.
people who let unnecessary options go
D.
people who shut the door
【单选题】所有者权益所包含的各项中,最普遍的两项是普通股和
【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