A:we can; by
B:can we; for
C:we can; round
D:can we, against
在数轴上有A,B两点,其中点A所对应的数是a,点B所对应的数是1.已知A,B两点的距离小于3,请你利用数轴.
(1)写出a所满足的不等式;
(2)数﹣3,0,4所对应的点到点B的距离小于3吗?
句子配对。
①How heavy is Tom?____ A. There are 15.
②How old is he?____B. He is 15years old.
③How much is the robot?____C. He weighs 51kg.
④How many boys are there under the tree?____D. It's September 15th.
⑤When is your birthday?____E. It's ¥15.
某商场以每件30元的价格购进一种玩具.通过试销售发现,逐渐提高售价,每天的利润增大,当售价提高到45元时,每天的利润达到最大值为450元,再提高售价时,由于销售量逐渐减少利润下降,当售价提高到60元时,每天一件也卖不出去.设售价为x,利润y是x的二次函数,则这个二次函数的解析式是( )