题目

阅读下面短文，掌握大意，然后从1-20各题所给的四个选项（A、B、C和D）中，选出最佳答案。 Do some animals have certain mental powers which human beings do not? Of course they have instincts(本能), but1this, I am sure that they can feel2things which we humans cannot. A personal experience3this to me. Some years ago, I had a dog named Howard. From the time that he was a baby dog, he was timid, so we named him 'Howard' to4with 'coward' (胆小鬼)! He was especially afraid of5. At the first hint of them, he would run crying into the house and hide under a table.叶绿体是植物进行光合作用的细胞器，下面有关叶绿体的叙述正确的是 A．叶绿体中的色素都分布在囊状结构的膜上 B．叶绿体中的色素分布在外膜和内膜上 C．光合作用的酶只分布在叶绿体基质中 D．光合作用的酶只分布在外膜、内膜和基粒上