摘要: [ 命题目的 ] 主要考查动词时态. [ 解题点拨 ] 首先去掉不合题意的A项.再分析句子可知该句为if引导的时间状语从句.因此可以用一般现在时表示一般将来时.故选D. 6人生百味 Early one morning, and an old woman was carrying a big bag of cabbages on her head to the market. She hoped to 1 them to the people from the town. The mountain road was 2 and the old woman was walking carefully, because she did not want to have 3 and lose her cabbages. Suddenly she 4 a loud bell, and a bicycle came round the corner and passed her and went very fast 5 the hill. The old woman had to jump to one side of the 6 so quickly that the bag of cabbages nearly fell into the valley. She looked up, and saw that a young boy was on the bicycle. He was 7 on without even looking round to see 8 the old woman was all right. The old woman began to shout, “Come back, young man! You dropped something! When he heard this, the boy stopped the bicycle so suddenly that he 9 fell off. Then he turned and began to 10 the bicycle back up the hill. “what is it? he asked, “what did I drop? “Little boy, the old woman answered, “You dropped your manners.

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(8分)材料   苏云金芽孢杆菌生长到一定阶段,菌体内一端形成芽孢,另一端形成一种被称为伴孢晶体的蛋白质晶体。菌体破裂后释放出芽孢和伴孢晶体,伴孢晶体本身并无毒性,是毒素的前体。当昆虫吞食伴孢晶体后,在肠道内碱性环境条件和特定的蛋白酶的作用下,伴孢晶体变成毒素分子,能使小肠上皮细胞萎缩退化,昆虫停食,最后脱水死亡。科学家利用苏云金芽孢杆菌的这个特性,在实验室大量培养,制成生物农药,洒在农作物上,让害虫吃后中毒死亡。或利用基因工程技术,把苏云金芽孢杆菌的抗虫基因转到农作物体内,培育出抗虫品种。请根据上述材料回答下列问题:

(1)上图中,切断a处的工具酶是____________ ,切断b处的酶是             ______。
(2)作为目的基因载体的细菌质粒往往要带有一个抗生素抗性基因,该抗性基因在基因工程中主要用于_____________________________________________________。
(3)苏云金芽孢杆菌的抗虫基因导入棉花细胞是否表达,最简便的检测方法是________________________________________________。
(4)苏云金芽孢杆菌的抗虫基因转到农作物体内后,也能产生伴孢晶体蛋白,说明___________________________。
(5)转基因工程改良动植物品种,最突出的优点是_____________________________ 。
(6)大面积种植抗虫棉对该地区生态平衡会造成怎样的影响?                                                   
①________________                       _____________
②_____________________                          _____。
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