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．

中华民族历史源远流长，传统文化博大精深，让国人引以为豪。请你写一段文字，使时期来威海参加夏令营的外国中学生朋友，既能简单了解中国的书法、戏曲、诗词（任选一种），更能感受到中华传统文化的魅力。（限80字以内）

如果一个数的相反数是负数，那么这个数一定是(    )

    Hello! My name is Tom. I1in Huangdu Middle School. My school is not new2beautiful. My teachers and classmates are nice to me. I love3very much.

    Our first class is48:00. We have four5in the morning and three in the afternoon. We have some6like English ,Chinese, math, art, but I don't like geography because it's not very7. Do you think so?

    I have lunch with my friends at school. Then we go to the8to read some books. After school, we like9basketball. I have a good10at school . I love my school.