题目

  The largest bird that cannot fly also happens to be the largest living bird in the world. This is the huge North African ostrich (鸵鸟). When the male is fully grown, he reaches a height of nearly eight feet and many weigh close to three hundred pounds. His wings are very small and the wing feathers are very soft, and therefore he does not fly. You have probably heard the old saying about “the foolish ostrich burying his head in the sand”. Well, the ostrich is not nearly as foolish as he is said to be. In the daytime, when the hen is sitting on the eggs, she does not want to b如图是番茄根细胞对K+吸收速率和氧分压的关系曲线,下列说法错误的是 (  ) A.氧分压为15时,曲线A→B段将延伸为M2 B.氧分压为0和10时,根细胞呼吸所需的酶有所不同 C.A→B段,ATP是限制根细胞对K+吸收速率的主要因素 D.B点以后,通过中耕松土可进一步促进对K+的吸收,曲线将延伸为M1
英语 试题推荐