Look,the boy is falling _____the bike.

Look,the boy is falling _____the bike.
Look,the boy is falling _____the bike.

Look,the boy is falling _____the bike.
Look,the boy is falling off the bike.
falling off 是固定搭配.
Noun
1.a noticeable deterioration in performance or quality; "the team went into a slump"; "a gradual slack in output"; "a drop-off in attendance"; "a falloff in quality"
(synonym) slump,slack,drop-off,falloff
(hypernym) deterioration,decline in quality,declension,worsening

Look,the boy is falling down the bike