近年来，我市遭受多种外来物种的入侵，如美国白蛾、黄顶菊、水葫芦、巴西龟等，对我市的生态环境造成了很大的影响．下面对外来入侵物种的有关描述，正确的是（　　）

①影响本地部分物种的生存，破坏本地生态平衡 

②造成本地部分物种的灭绝，危及本地生物的多样性 

③外来物种的入侵，有利本地生物优胜劣汰 

④外来物种的入侵，丰富了本地生物的多样性．

将直径为60cm的圆形铁皮，做成三个相同的圆锥容器的侧面（不浪费材料，不计接缝处的材料损耗），那么每个圆锥容器的底面半径为          （    ）

中学生小王在上学路上，发现马路上的井盖破碎，成了一个陷阱，行人都在绕行。小王停下车，找了些砖块，在危险处围了个警戒圈，并及时向有关部门打电话反映情况。结果她上学迟到了。下列对小王的行为，评论正确的是（     ）

阅读短文，判断下列句子“正确”还是“错误”。

    Which Skirt to Wear?

    Tina is 8 years old, and follows her own ideas. When her parents tell her to do something, she always doesn't do it. Today, she will go to a friend's birthday party. She is now choosing skirt to wear. She has three skirts: a blue skirt, a white one and a yellow one. She asks her father, “Which one is the best?” her father says, “I think the blue one is the best.” Then she asks her mother, “Which one do you think is the best?” Her mother answers, “The white one, of course!” Tina says, “Thank you.” Then she puts on the yellow skirt and goes out.