Riding a bike is exercise.为什么Riding不能用ride?

Riding a bike is exercise.为什么Riding不能用ride? Riding a bike is agood e__ Joe is riding a bike picture 画riding a bike （对画线句子提问） What is mingming doing?He is riding a bike. bike is a her riding hobby 连词成句 riding Lisa a is bike连词成句 Is the boy riding a bike?的答句 Riding a bike to school is good e_____.首字母填空 Riding a bike is faster than walking.同义句：Riding a bike___ ____time ____walking. Riding a bike is faster than walking 改同意句Riding a bike ___ ___ time ___walking riding a bike怎么读 What about riding a bike? jane is riding a bike.（改成否定句） jine_________ a bike he is crazy music.he listens to music o when he is riding a bike. What is your pen pal‘s hobby?A.He likes riding a bike.B.He likes ride a bike. _________old bike Li Lei is riding!A what a B what C what an Dhow look.lucy is a new bike today.A.jumping B .running C.riding .D takeing急 Why _______ go bike riding with us?why _______ go bike riding with us?A.don’t B.not C.is D.can’t说出理由