花卉的栽植深度一般以原土痕为标准，即浇水以后，原苗床栽植深度_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题判断题

花卉的栽植深度一般以原土痕为标准，即浇水以后，原苗床栽植深度为移植的栽植深度。

答案

参考答案：对

填空题

阅读下列说明和C代码，将应填入 (n) 处的字句。

[说明]

设某一机器由n个部件组成，每一个部件都可以从m个不同的供应商处购得。供应商j供应的部件i具有重量w_ij和价格c_ij。设计一个算法，求解总价格不超过上限cc的最小重量的机器组成。

采用回溯法来求解该问题：

首先定义解空间。解空间由长度为n的向量组成，其中每个分量取值来自集合1，2，…，m)，将解空间用树形结构表示。

接着从根结点开始，以深度优先的方式搜索整个解空间。从根结点开始，根结点成为活结点，同时也成为当前的扩展结点。向纵深方向考虑第一个部件从第一个供应商处购买，得到一个新结点。判断当前的机器价格(c₁₁)是否超过上限(cc)，重量(w₁₁)是否比当前已知的解(最小重量)大，若是，应回溯至最近的一个活结点；若否，则该新结点成为活结点，同时也成为当前的扩展结点，根结点不再是扩展结点。继续向纵深方向考虑第二个部件从第一个供应商处购买，得到一个新结点。同样判断当前的机器价格(c₁₁+c₂₁)是否超过上限(cc)，重量(w₁₁+w₂₁)是否比当前已知的解(最小重量)大。若是，应回溯至最近的一个活结点；若否，则该新结点成为活结点，同时也成为当前的扩展结点，原来的结点不再是扩展结点。以这种方式递归地在解空间中搜索，直到找到所要求的解或者解空间中已无活结点为止。

[C代码]

下面是该算法的C语言实现。

(1)变量说明

n：机器的部件数

m：供应商数

cc：价格上限

w[][]：二维数组，w[i][j]表示第j个供应商供应的第i个部件的重量

c[][]：二维数组，c[i]D]表示第j个供应商供应的第i个部件的价格

bestW：满足价格上限约束条件的最小机器重量

bestC：最小重量机器的价格

bestX[]：最优解，一维数组，bestX[i]表示第i个部件来自哪个供应商

cw：搜索过程中机器的重量

cp：搜索过程中机器的价格

x[]：搜索过程中产生的解，x[i]表示第i个部件来自哪个供应商

i：当前考虑的部件，从0到n-1

j：循环变量

(2)函数backtrack

int n=3;

int m=3;

int cc=4;

int w[3][3]=1,2,3,3,2,1,2,2,2;

int c[3][3]=1,2,3,3,2,1,2,2,2;

int bestW=8;

int bestC=0;

int bestX[3]=0，0，0;

int cw=0;

int cp=0;

int x[3]=0，0，0;

int backtrack (int i)

int j=0;

int found=0;

if(i＞n-1) /*得到问题解*/

bestW=cw;

bestC=cp;

for(j=0; j＜n; j++)

(1) ;

return 1;

if (cp＜=cc)(/*有解*/

found=1;

for(j=0; (2) ; j++)

/*第i个部件从第j个供应商购买*/

(3) ;

cw=cw+w[i] [j];

cp=cp+c[i] [j];

if (cp＜=cc&& (4) )/*深度搜索，扩展当前结点*/

if (backtrack(i+1)) found -1; )

/*回溯*/

cw=cw - w[i] [j];

(5) ;

return found;

（2）处应填（）。

完形填空

阅读下面短文，掌握其大意，然后从l6-35各题所给的A、B、C、D四个选项中，选出最佳选项。
When I was about 13, my father would take me on short outings on Saturdays.On the way home, Dad      stopped at the Dairy Queen for 10-cent ice creams. I couldn't     it. but I could pray from the    we started heading home to that corner where we would either go straight for the ice cream or      and go home empty-handed. That corner    either mouth-watering excitement or    .
On one special day. we were heading home. and again I was praying for the   sound of his offer. It    . "Would you like an ice cream today?" "That sounds great, Dad!" But then he said, "How would you like to      today?"
Twenty cents! My mind reeled(震惊). I could afford it. I got a weekly allowance of 25 cents. plus some      for odd jobs. But      it was my money, ice cream wasn't a good use of it. In a fit of      , I said, "Well, in that case. I guess I'll     ." My father just said, "Okay, Son."
But as we headed home, I realized how wrong I was and begged him to     . But he just said. "That's okay. We don't really need one." I felt       for my selfishness and ungratefulness. He didn't mind, or     act disappointedly.
I     that generosity goes two ways and gratefulness sometimes costs more than "thank you". On that day gratefulness would have cost 20 cents and it would have been the    ice cream I'd ever had.
I'Il tell you one more thing. We   another trip the next week. As we      the corner, I said, "Dad, would you like an ice cream today? My treat."

D．disappointment

C．interesting

D．selfishness

A．unsatisfied

D．acknowledged

B．prepared for