题干

现有4个纯合南瓜品种,其中2个品种的果形表现为圆形(圆甲和圆乙),1个表现为扁盘形(扁盘),1个表现为长形(长)。用这4个南瓜品种做了3个实验,结果如下:

实验1:圆甲×圆乙,F1为扁盘,F2中扁盘:圆:长=9:6:1

实验2:扁盘×长,F1为扁盘,F2中扁盘:圆:长=9:6:1

实验3:用长形品种植株的花粉分别对上述杂交组合的P1植株授粉,其后代中扁盘:圆:长均等于1:2:1。综合上述实验结果,请回答:

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同类题5

请认真阅读下面短文,从短文所给的A、B、C、D四个选项中,选出最佳选项。

    Raynor Winn and her husband Moth became homeless due to their wrong investment. Their savings had been 1 to pay lawyers' fees. To make matters worse, Moth was diagnosed(诊断)with a 2 disease. There was no 3, only pain relief.

    Failing to find any other way out, they decided to make a 4 journey, as they caught sight of an old hikers'(徒步旅行者)guide.

    This was a long journey of unaccustomed hardship and 5 recovery. When leaving home, Raynor and Moth had just £320 in the bank. They planned to keep the 6 low by living on boiled noodles, with the7hamburger shop treat.

    Wild camping is 8 in England. To avoid being caught, the Winns had to get their tent up 9and packed it away early in the morning. The Winns soon discovered that daily hiking in their 50s is a lot 10 than they remember it was in their 20s. Raynor 11 all over and desired a bath. Moth, meanwhile, after an initial 12, found his symptoms were strangely 13 by their daily tiring journey.

    14, the couple found that their bodies turned for the better, with re-found strong muscles that they thought had 15 forever. "Our hair was fried and falling out, nails broken, clothes 16 to a thread, but we were alive."

    During the journey, Raynor began a career as a nature writer. She writes, "17 had taken every material thing from me and left me torn bare, an empty page at the end of a(n) 18 written book. It had also given me a 19, either to leave that page 20 or to keep writing the story with hope. I chose hope."