题目解析：
【题目翻译】根据第3段，对于辫状河，下列各项均属实，除哪一项外？
A：由于一些河道淤积泥沙，形成了新的河道，它们在河漫滩上来回移动。
B：它们携带的沉积物往往大小非常相似。
C：它们有时会在中间通道的酒吧。
D：它们的一些通道是由于其他通道溢出而创建的。
【判定题型】：根据题干中出现的大写“EXCEPT”/"NOT" 等其他明显表示否定的词，可以判定本题为否定事实信息题，需要找出与原文信息不符的那个答案。
【关键词定位】根据关键词“back and forth”定位到第3段这2句话“The bars gradually fill a channel, forcing the stream to overflow its banks and erode new channels. As a result, a braided stream flows simultaneously in several channels and shifts back and forth across its floodplain.”
【选项分析】
A选项中，这两句话说，沙洲会渐渐填满河道，迫使水流溢出堤岸，侵蚀出新的河道。结果是，辫状河在多个河道同时流动，并在河漫滩上来回流动。所以A选项完全符合原文，故排除。
B选项说，辫状河所携带的泥沙的大小非常类似。这在文中并没有提及，故B选项为正确答案。
C选项中，根据关键词“mid-channel bars”定位到这句话“The stream dumps the excess sediment, forming mid-channel bars.”辫状河因为携带了过多的泥沙，所以会形成河心沙洲。故C选项符合原文，排除。
D选项中，根据关键词“overflow”，定位到这一句“The bars gradually fill a channel, forcing the stream to overflow its banks and erode new channels.”由于河道被堵塞，所以河流会溢出堤岸，形成新的河道，因此D选项符合原文，排除
Most streams flow in a single channel. In contrast, a braided stream flows in many shallow, interconnecting channels. A braided stream forms where more sediment is supplied to a stream than it can carry. The stream dumps the excess sediment, forming mid-channel bars. The bars gradually fill a channel, forcing the stream to overflow its banks and erode new channels. As a result, a braided stream flows simultaneously in several channels and shifts back and forth across its floodplain. Braided streams are common in both deserts and glacial environments because both produce abundant sediment. A desert yields large amounts of sediment because it has little or no vegetation to prevent erosion. Glaciers grind bedrock into fine sediment, which is carried by streams flowing from the melting ice. If a steep mountain stream flows onto a flat plain, its gradient and velocity decrease sharply. As a result, it deposits most of its sediment in a fan-shaped mound called an alluvial fan. Alluvial fans are common in many arid and semiarid mountainous regions.
