Jack narrowly fell off the cliff, but managed to until help came.
A. keep on
B. hang on
C. live on
D. count on
网友回答
A. keep on
(答案→)B. hang on
C. live on
D. count on
解析：句意：杰克差一点就从悬崖上掉下去了，但是他设法停住了直到有人来帮忙。keep on继续； hang on停住； live on以……为食； count on指望，依靠。根据句意故选B。