洛氏硬度C标尺所用的压头是（ ）。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='24891' and id < 2124431 and id<>'2124431' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='24891' and id > 2124431 and id<>'2124431' order by id asc limit 5