Periodically , the lamellae become enlarged, forming flattened, membrane - enclosed vesicles called thylakoids.片层周期性地扩展, 形成扁平的有膜为界的囊,称为类囊体.Mortality is the number or volume of trees periodically rendered unusable through...
当他们靠近时,大象又吼又跺脚。The elephants trumpeted and stamped their feet at their approach.一群大象缓慢而笨拙地穿过平原,朝水潭走去。A herd of elephants lolloped across the plains towards a watering hole.他的精心之作是一件大象雕塑。His tour de force is an elephant s...