题目

DBeyond two or three days，the world’s best weather forecasts are doubtful, and beyond six or seven they are worthless.The Butterfly Effect is the reason. For small pieces of weather—to a global forecaster，small can mean thunder—storms and blizzards（暴风雪）—any prediction becomes worse rapidly. Errors and uncertainties increase，from dust devils and storms up to continent-size eddies（旋涡）that only satellites can see.The modern weather models work with net-like points sixty miles apart，and even so，some starting data have to be guessed，since ground stations and sa蜈蚣、蚰蜒和马陆等动物的身体上有许多对步足，其运动方式是（　　） A、行走B、爬行C、飞行D、游泳