if you are good enough,Tom,you ______have a bicycle as your your birthday gift

问题描述:

if you are good enough,Tom,you ______have a bicycle as your your birthday gift
A.willB.shall C.mustD.may
答案选B

shall 有期许的含义,比其他的三个选项更符合语句含义;
will也有这层意思,但是做为奖励用shall更合适.
must,may都是一种推断的用词,不太符合语境.