题目

棉蚜虫被瓢虫捕食时，被捕食的蚜虫会立即释放一种报警信息激素，于是周围的蚜虫纷纷跌落，这种现象属于( ) A．种内竞争                            B．种内互助 C．种间互助                 D．互利共生 答案：BFor as long as I can remember, Grandma's plentiful tomato garden has been a sign of summer's end. Each September, just as the decreased heat of the sun suggests cooler days, Grandma requests my help in her tomato garden. She convinces me she cannot pick tomatoes without my youthful eyes and quick mind. She says we need to examine each tomato and agree on its readiness for picking. While Grandma's request for my help in the tomato garden is always the same, her desire for my help seems to increase each year. Grandma has eyes for finding even the tomatoes hidden by undergrowth and other tomatoes. I, however, just turn circles looking for the ones I think Grandma will like. I spot what looks like a ripe tomato, head in its direction, and then get sidetracked by another that appears to be equally ripe. I usually end up watching Grandma and trying to stay out of her way, which seems the only way my eyes and mind are useful. 　 There we are, lost in the tomato vines（藤）. Grandma's eyes are always knowing, and they are no different in the vegetable garden. From afar she spots what looks like a ripe tomato. As she walks toward the garden, she evaluates the tomato for a second time. but from a different angle. I already know it will end up in the basket with the pile of others Grandma has carefully chosen. However, Grandma acts as if she needs a final look to be sure. She calls me to her side. kneels beside the vine while enjoying the warmth of the fading hand. She turns each round, red ball toward the sunlight before disconnecting it from the vine with a half-hearted smile. She then looks at me. I nod my head and smile. Grandma assumes I smile in agreement with her tomato selection. I know I smile, instead, at her1.Why does Grandma ask the author to go to the tomato garden with her?A.He can help pick more tomatoesB.He can learn the hardship of laborC.She enjoys staying with him while workingD.She tries to share tomato harvest with him2.The second paragraph shows that the writer _________A.isn’t good at picking tomatoesB.doesn’t like to stay with GrandmaC.thinks his eyes and mind are usefulD.is trying to be out of Grandma’s sight3.What’s the best title of the story?A.Gardening—good for my GrandmaB.Growing GrandmaC.Gardening—good for my growthD.Picking tomatoes