皮带主传动张力在每次测量之前，至少将皮带转动（）圈。

A.121+10Hz约等于9daN
B.133+10Hz约等于9daN
C.152+10Hz约等于9daN
D.172+10Hz约等于9daN

A.133+10Hz约等于10-11daN
B.167+10Hz约等于10-11daN
C.172+10Hz约等于10-11daN
D.189+10Hz约等于10-11daN

A.1
B.2
C.3
D.4