英國首相易人(2)

科學(xué)60秒:逃離

Sea lampreys leave as the invasive species chomps through the Great Lakes. Attempts to manage them have relied in part on pheromones that attract the animals. After being trapped, they’re eithe...

初中英語牛津八年級(jí)下01(2)

講述意大利比薩斜塔Why does the tower lean? In fact,it was already leaning while they were building it. As soon as three floors had been built,by 1178, it began to lean as the ground beneath it...

plants in the deserts

Plants in the DesertsSome cacti, like the saguaro, grow to tree size, but true trees need more moisture than most desert environments can supply, so they are scarce on deserts. Close to streambed...