让奥运火炬登上珠峰,是北京在申办2008年奥运会时对世界的一个承诺,也是奥林匹克

题型:问答题

问题:

让奥运火炬登上珠峰,是北京在申办2008年奥运会时对世界的一个承诺,也是奥林匹克史无前例的壮举.奥运火炬“祥云”使用的燃料为丙烷(化学式C3H8).

(1)丙烷燃烧的化学方程式为:C3H8+5O2

 点燃 
.
 
______CO2+______H2O,请你帮助完成化学方程式的配平;

(2)请计算22g丙烷完全燃烧需要消耗氧气的质量.

考点:化学反应方程式的计算化学反应方程式的配平
题型:问答题

女性生殖器最常见的良性肿瘤是()。

A.子宫肌瘤

B.浆液性囊腺瘤

C.黏液性囊腺瘤

D.皮样囊肿

E.纤维瘤

题型:问答题

如图所示,电源电动势为E,内电阻为r,电压表和电流表均为理想电表,L为白炽灯,其阻值随温度变化,R为变阻器.当变阻器的滑臂向右滑动时(  )

A.V1和A两表的读数之比增大

B.V2和A两表的读数之比增大

C.V1表的变化量和A表的变化量的比值不变

D.V2表的变化量和A表的变化量的比值减小

题型:问答题
 
短文改错。
      
     Not too long ago, people can't go scuba diving on
Hainan Island, or anywhere else. This were because  
there was no machine allowing  person to breathe    
under water for long time. In 1943 Jacques
Cousteau and his friend made it possible by invent the scuba    
machine. Cousteau was very interested on diving        
deep into the sea, but wanted to be an explorer. He    
bought a ship and used them to explore under the sea.
He also was liked to make videos. As he explored
the sea, he took pictures and videos of many thing that  
people had never seen before.  
1.                                                
2.                                                
3.                                                
4.                                                
5.                                                
6.                                                
7.                                                
8.                                                
9.                                                
10.                                              
题型:问答题

在制订主生产计划,必须首先了解约束条件,根据产品的轻重缓急来分配资源,将关键资源用于关键产品。( )

题型:问答题

两同学用如图所示方法做共点力平衡实验。M、N为摩擦不计的定滑轮,O点是轻质细绳OA、OB和OC的结点,桌上有若干相同的钩码,某同学已经在A点和C点分别挂了3个和4个钩码,为使O点在两滑轮间某位置受力平衡,另一同学在B点挂的钩码数应是()

A.1个

B.3个

C.5个

D.7个

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