胶圈接口时,纵坡大于()%时,应采取防止管道下滑的措施。
A.12
B.15
C.18
D.20
参考答案:C
After the experiment, the teacher will ask us what the experiment _____. [ ]
A. has
B. proves
C. say
D. tell
宋金元时期对伤寒论的注解本有()、()、()《伤寒百证歌》。