细菌蛋白质在极端环境条件下可通过肽链之间的二硫键维持稳定．已知不同的多肽产物可因分子量不同而以电泳方式分离．如图所示是一个分析细菌蛋白质的电泳结果图，“﹣”代表没加还原剂，“+”代表加有还原剂，还原剂可打断二硫键，“M”代表已知分子量的蛋白质，右侧数字单摆蛋白质或多肽的相对分子量，根据如图所示的结果，下列哪个图案最能代表该细菌原本的多肽结构（注意：“﹣”代表二硫键）（    ）

两只相同的电阻，分别通以正弦形的交流电和方波形的交流电。两种交流电流的最大值相等，如图所示。在正弦形交流电的一个周期内，正弦形的交流电在电阻上产生的焦耳热Q₁与方波形交流电在电阻上产生的焦耳热Q₂之比Q₁/Q₂等于(　　)

        Tom and Fred were talking about the year 2050.
　　“What will 1 be like in the year 2050?” asked Tom.
　　“I don't know,” said Fred. “What do you think?”
　　“Well, no one knows. But it is 2 to guess,” said Tom. “In the year 2050 everybody will carry a pocket (袖珍) 3. The computer will give people the 4 to all their problems. We shall all have telephones in our pockets,5 . And we'll be able to talk to our friends all over the world. Perhaps(也许) we’ll be able to 6 them at the same time. Machines will do 7of the work, and people will have more8. Perhaps they will work only two or three days a week. They will be able to fly to the moon by spaceship and spend their holidays there.”
　　“I'm very 9to hear that. I hope to fly to the moon. And I hope I'll be able to live 10,” said Fred. “Won't that be interesting? Just like a fish.”

____既是苏德战争的转折点，又是第二次世界大战的转折点

观察下面漫画，回答下列问题