图中M表示南半球某地太阳高度的日变化状况。读图回答11题。11．此日在距该地6660千米的A地比杭州（30°N）日出晚1小时（提示：杭州一年中昼最长约为1
基因的分离和自由组合发生在 A．前者减数第一次分裂，后者减数第二次分裂 B．都是减数第一次分裂 C．前者减数第一次分裂，后者受精作
The weather is ______ in London, and umbrellas are very popular.A．rainyB．sunnyC．windyD．rain
亚硝酸钠可将人体血红蛋白中的Fe2＋氧化为Fe3＋，生成高铁血红蛋白而丧失与O2结合的能力，误食亚硝酸钠可服维生素C缓解，下列对亚硝酸钠和维生素C
Cars are very popular in America. When the kids are fourteen years old. They dream of having their own ____1___. Many students work after school to ___2___ a car. In most places ____3___ people learn
A. year ago August, Dave Fuss lost his job driving a truck for a small company in west Michigan. His wife, Gerrie, was still working in the local school cafeteria, but work for Dave was scarce, and th
张老师上班途中要经过3个十字路口，每个十字路口遇到红、绿灯的机会都相同，张老师希望上班经过每个路口都是绿灯，但实际上这样的机会是（
When I was thirteen, my family moved from Boston to Tucson, Arizona. 36 the move, my father 37 us in the living-room on a freezing January night. My sisters and I sat around the fire, no
