世界上最高的高原形成的地质年代是[ ]
A.新生代
B.中生代
C.古生代
D.元古代
答案:A
A good idea _________ to him, and he knew _______ to do next.
A.happened , what
B.appeared ,how
C.occurred ,what
D.arrived ,how
柔性护坡技术含义及优缺点?