题目

植物体细胞融合完成的标志是（ ）A. 产生新的细胞壁 B. 细胞膜发生融合C. 细胞质发生融合 D. 细胞核发生融合 答案：【答案】A【解析】植物体细胞杂交的完成，首先把来自两个植物的细胞融合为一个杂种细胞，然后把这个杂种细胞培养成一个新的植物体。在植物体细胞杂交过程中，融合细胞外面形成新的细胞壁是植物体细胞融合完成的标志，A正确；细胞膜发生融合，属于植物体细胞融合的过程，B错误；细胞质发生There was a little boy with a bad temper（脾气）.His father gave him some nails（钉子）to drive into the fence (栅栏)when he lost his temper .The first day the boy drove 37 nails into the fence .Then it began to become less . He found it was easier to hold his temper than to drive those nails into the fence .Finally the day came when the boy didn’t lose his temper at all . He told his father about it and the father suggested that the boy should now pull out one nail for each day that he  held his temper .The days passed and the young boy was finally able to tell his father that all the nails were gone .The father took his son by the hand and led him to the fence .He said , “You have done well ,my son ,but you look at the fence . It will never be the same .When you say things in anger ,they leave a scar（痕迹）just like this one .You can put a knife in a man and draw it out . It won’t matter how many times you say I’m sorry ,the wound (伤口)is still there .A verbal （言语）wound is as bad as a physical(肉体)one.1.Who was in a bad temper ?A.the boy’s fatherB.the boy’s friendC.the little boyD.a man2.The word “it” in “it began to become less”refers to (指) ________ .A.the first dayB.the fenceC.the nailsD.the boy’s temper3.The way of pulling out nails is to _________.A.make one’s temper lessB.make one hold one’s temperC.leave a scar on somsoneD.hurt someone .4.The boy thought that _______A.it was easy for him to drive the nails into the fence .B.driving nails into the fence is easier than holding his temper .C.holding his temper is easier than driving nails into the fence .D.it was easy for him to lose his temper after driving nails .5.We learn from the reading that _______ .A.the father was a man with bad temper .B.it took a long time for the boy’s temper to become less.C.the father was good at helping one who is easy to lose temper .D.the boy was good at driving nails into the fence .