阅读下列材料：
材料一 在唐初诸帝时代，中国的温文有礼、文化腾达和威力远被，同西方世界的腐败、混乱和分裂对照得那样地鲜明，以致在文明史上立刻引起一些最有意思的问题。中国由于迅速恢复了秩序和统一而赢得了这个伟大的领先。                     
——韦尔斯《世界史纲》
材料二 清朝在康熙、雍正、乾隆帝时期，经过同外部侵略势力及内部民族分裂势力的一系列重大斗争，建立起一个空前统一和巩固的国家。这就基本奠定了今天中国疆域的规模。
——张传玺主编《中国古代史纲》
材料三 内战首先使美国原来宪政机制中分裂的主权得到了统一。它为美国大工业化的发展，准备了条件。这个是一个先行，如果说，主权得不到统一，领土不能够得到统一，或者劳动力体制得不到统一的话，后面的大工业化还会推迟，或者不会产生这么大的效果。
很多美国历史学者认为，南北战争是美国历史上的一道分水岭。联邦政府从此变得强大起来，美国的农业、工业以及整个国家都发生了重要的转变。    
——《大国崛起 美国》

藻类植物的大量繁殖易引起赤潮或水华现象.（判断对错）．

    I have a best friend. His name is James. He is from the USA. We look totally(完全) different！I have blonde hair and he has red hair. I wear glasses，but he doesn't. I am short and he is very tall. We both love to sing and dance. But I'm very outgoing and he is very quiet.

    Sam Green

    I don't really have a best friend but one of my good friends is Kristi. She is from America. I sometimes call her Kwiti. She is funny and kind. And she really cares about(关心) everyone and almost everything. She became one of my good friends at the age of five.

    Mary Smith

    My best friend's name is Edna. She is from Australia. She likes to talk a lot and hardly keeps quiet. Edna has curly brown hair and brown eyes. She always makes me laugh. Also，she sometimes helps me with my homework.

    Lisa Brown

    I have a best friend from India. Her name is Sinsha. I call her Kuttu. She is short. She has a round face and black eyes. She has long black hair. You can hardly get sad or angry if you're with her. She often makes me happy.

    Donna

图中，表示南美洲的是（　　）