问题
问答题 简答题
马铃薯块茎“长疥”是什么原因？
答案
参考答案：
是马铃薯疮痂病菌造成的。马铃薯疮痂病菌为疮痂链霉菌，属放线菌，土壤和带病种薯为初侵染源，主要为害薯块。初在薯块表面产生褐色小斑点，后扩大为近圆形至不规则形的木栓状病斑。常多个病斑汇合成片，表面粗糙，呈疮痂状硬斑，群众称之为“疥”，病斑仅限于薯皮，不侵入薯肉。
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马铃薯块茎“长疥”是什么原因？
参考答案：
是马铃薯疮痂病菌造成的。马铃薯疮痂病菌为疮痂链霉菌，属放线菌，土壤和带病种薯为初侵染源，主要为害薯块。初在薯块表面产生褐色小斑点，后扩大为近圆形至不规则形的木栓状病斑。常多个病斑汇合成片，表面粗糙，呈疮痂状硬斑，群众称之为“疥”，病斑仅限于薯皮，不侵入薯肉。
| 完形填空。 阅读下面短文，掌握其大意，然后从各题所给的A、B、C、D四个选项中， 选出可以填入空白处的最佳选项，。 | ||||
| Louise was 72 years old and she lived by herself. The first thing she noticed when she came downstairs that Sunday morning was that her 1 window was open. In fact, it was so wide open that she had 2 closing it. Then she realized that things were not in their proper 3 . Finally, when she found her empty 4 on the kitchen table, she realized the awful 5 . At first, she didn’t know what to do. Then she decided to 6 her son, Derek. Derek’s wife Sybil answered the phone, "It’s your mother," she 7 him, coldly. Louise told Derek about the open window, about things being in the wrong places and about the 8 missing from her purse. "All right," said Derek, "Don’t 9 anything. I’ll be 10 in half an hour." Louise 11 and made herself a pot of tea and some toast. Then she went from room to room wondering 12 anything else was missing. When Derek arrived, he was content to 13 her looking so calm. "Have you rung the 14 ?" he asked. "No? Then I’ll do that straight away." So he rang the police. As it was Sunday, 15 the only detectives were out. However, the police were polite, but vague （含糊的）. "We’ll send 16 round as soon as possible,"they said. Derek telephoned his wife. "I’m not sure when I’ll be home, love,"he told her. "I’ve got to 17 for the police." While Derek and his mother waited, Derek 18 the catches（挂钩）on the windows and locks on the doors. All of them were old and some of the catches hardly 19 at all. Derek felt 20 . His mother was an old woman, after all. "I’ll have to change all these," he told her. | ||||
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