-- Call me when you get home.
-- OK, ________.
A:I must
B:I can
C:I will
D:I may
The city is 2, 000 kilometers away from here. You'd better ________.
某次知识竞赛共20道题,每一题答对得10分,答错或不答都扣5分,小英得分不低于90分.设她答对了x道题,则根据题意可列出不等式为( )