【引言】人生在世,是踢着石头走路的。河流是踢着石头大步迈进的典范。河水下的石头在流动,石头渐失棱角而变成越来越小的鹅卵石,有的鹅卵石最后成为了细沙。执著的、比石头更强硬的是河流的脚! [Introduction] life is alive, is kicking the stone walk. The river is a great example of kicking the stone. Flowing stones under the water, the stone gradually become corners and become smaller and smaller pebbles, and some pebbles eventually became fine sand. Persistent, harder than the river is the foot of the river!