题目

农业上常用的有种方法如下： a．甲品种 × 乙品种→F1→F1自交→F2个人工选择→自交→F3→人工选择→自交……→性状稳定的新品种 b．甲品种 × 乙品种→Fl→F1花粉离体培养得到许多小苗→秋水仙素处理→若干植株→F1人工选择→性状稳定的新品种 c．正常幼苗→秋水仙素处理→人工选择→性状稳定的新品种 d．种子搭载人造卫星到太空→返回地面种植→性状稳定的新品种 e．获取甲种生物的某基因→通过某种载体将该基因带入乙种生物→性状稳定的新完形填空(共20小题；每小题1.5分，满分30分)阅读下面短文，从短文后所给各题的四个选项(A、B、C、D)中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。第二节完型填空(共20小题，每小题1.5分，满分30分)It was New Year’s night, An aged man was standing at a window. He raised his mournful（悲哀的）eyes towards the deep  36 sky, where the stars were  37 like white lilies(百合花)on the surface of a clear calm lake．Then he threw them on the earth．Where a few more  38 people than himself now moved towards their certain goal-the  39 ，He had already passed sixty of the  40  leading to it，and he had brought from his journey nothing but errors and regret．Now his health was poor，his mind  41 ，his heart sorrowful，and his old age short of  42．The days of his youth appeared like dreams before him．and he recalled the  43 momentwhen his father placed him at the  44 to the two roads-one leading to a  45 ．sunny place．covered with flowers，fruits and resounding with soft，sweet songs；the other 1eading to a deep，dark cave．which was endless． 46 poison flowed instead of water and where deviIs(恶魔)andpoisonous snakes hissed and crawled．He saw the  47  fading away in the darkness．and these were the days of his  48 life；He saw a star fall from the sky and disappeared，and this was the  49 of himself．His regret，which was like a sharparrow．Struck deeply into his heart．Then he remembered his friends in hischildhood．who entered on life together with him．But they had  50 to success and were nowhonored and happy on this New Year’s nightThe clock in the high church tow struck and the sound made him remember his parents’early love for him．They had taught him and  51 to God for his good．But he chose the 52way．With shame and grief he   53  no longer look towards that heaven where his father lived．His darkened eyes were full of tears，and with a despairing  54  ，he burst out a cry；“Come back，my  55  days!Come back!”36．A．grey           B,blue           C. black        D. cloudy37．A．floating         B, flashing       C hanging      D shinning 38．A．purposeless     B purposeful      C hopeful      D hopeless39．A．house          B tomb         C church        D birthplace40．A．dreams         B moments      C incidents      D stages 41．A．strange         B pale           C blank        D shallow42．A．allowances      Bcomforts        C experiences   D  memories43．A．serious         B awful          C tough         D desperate44．A．end            B entrance        C origin        D base45．A.  lonely          B noisy           C quiet        D peaceful 46．A．which          B that             C whose       D where47．A．people         B lights            C  stars       D clouds48．A．accustomed     B rewarded         C wasted      D occupied49．A．symbol          B fate             C future       D outcome50．A．lost their heart B devoted their attention C．made their way D given their way51．A．prayed       B attached         C adjusted      D turned52．A．ordinary     B unfamiliar        C wrong        D difficult 53．A．would      B could            C should         D dared54．A．anxiety     B effort            C patience       D attempt55．A．early       B good             C old           D shamdful