砂岩杂基的含量在20%,这种砂岩应为()?
A.长石砂岩
B.净砂岩
C.杂砂岩
D.岩屑砂岩
参考答案:C
建筑安全技术
以下不属于建筑施工过程中五大伤害的是( )。
A.高处坠落
B.机械伤害
C.起重伤害
D.坍塌
Many things that were once considered useful and _____, for example, tobacco, is now thought harmful.
A.beneficial
B.suitable
C.fulfilling
D.accessible