在自然界,适合于环境条件的生物被保留下来,不适应的被淘汰,这就是()。
参考答案:自然选择
What impressed me in Greece was that the oceans _______ the islands were deep blue and many cities lay on the bay.
A.surrounding
B.being surrounded
C.surrounded
D.surround
向占用区间(),向占用线(),未构成一般B类以上事故的,为一般C类事故。