I'd like a bigger one,这里big为什么用比较级

I'd like a bigger one,这里big为什么用比较级 It's not bigger than our pianet It's much__________.I'd like a bigger pianet.英语六年级上册活动手册21页的答案 (1) I'd like a large pizza( )onions on it This room is too small.I would like a bigger one _______ A.to live B.ilive C.live D.to live in I’d like to do_____I like on weekends.A、that B、whether C、what D、which I'd like to swim on Saturday.Would you like to go____me?A andB forC eith would you like to a --------car ride this evening ---i'd like to.A.walk on B.take on C.go on D.make on I'd like to go on a Disney Cruise.在此句中go on I’d like（ ）eggs on the farm.A.collect B.collects C.collecting D.collected I’d like to trek ______ the jungle.A.through B.across C.over D.on Will there be____there just like people on Earth?A.waterB.lifeC.airD.sound请说明理由,Marth is much____than Earth beautiful it's farther from the sun.A.hotter B.colder C.bigger D.smaller请说明理由, I一撇d like ____ thin bamboo sticks and thin paper _____ a bigger kite.A.to use,make B.to use,to make C.use,to make D.use,make 连词成句：bigger yours than bag think my is I.make snowman winter like I in to a. I like the one _ pictures _ it.A.has;on B.have;on C.with;on D.with;in I'd like to _ a Disney Cruise.I'd like to _ a Disney Cruise.A,go on B,go to C,be in D,be for I'd like a big cake （）my party.A.in B.at C.on “I'd like have a ” I'd like a cold