Plants growing in the semi - fixed sand dunes , on the other hand , were less branchy with a larger number of first - year shoots which were longer , and grew faster ; their leaves were longer and wider with a low length / width ratio . the characteristics of the branching system and leaf dimensions of the plants in fixed sand dunes were rather intermediary between those of the above . the frequency distribution and their frequency in the herb layer the scrubs also varied with habitats 丘间低地的黄柳灌丛当年枝平均长度增加缓慢，短枝条的比例较高，当年枝枝长频度分布峰值偏左，叶片短而狭，长宽比大；与之相比，分布于半固定沙丘的灌丛当年枝平均长度增加较快，长枝条比例较高，叶片长而宽，长宽比小；固定沙丘上的上述特征大致介于二者之间。
4.
Instead of subsiding as night drew on , it seemed to augment its rush and deepen its roar : the trees blew steadfastly one way , never writhing round , and scarcely tossing back their boughs once in an hour ; so continuous was the strain bending their branchy heads northward - the clouds drifted from pole to pole , fast following , mass on mass : no glimpse of blue sky had been visible that july day 入夜，风势非但没有减弱，反而越来越强，咆哮声越来越响。树木被一个劲儿地往一边吹着，从不改向，一个小时里，树枝几乎一次都没有朝反方向倒去，树梢一直紧绷着往北弯着。云块从一头飘到另一头，接踵而来，层层叠叠，七月的这一天看不到一丝蓝天。
