单项选择题
A.1 B.5 C.10 D.20
A.砾岩 B.玄武岩 C.砂岩 D.石灰岩
A.90° B.60° C.45° D.30°
A.95% B.90% C.85% D.80%
微信扫一扫,加关注免费搜题