坐标原点）的最大值为2，则m=____．
一个数十位是2，个位上的数比十位上的数小2．它是____．
Students used to information from newspapers or magazines, but now they are used to for it on the Internet directly.
——Tom is ill. When shall we go to see him, on Saturday or on Sunday?—— ________. Either will do.
下列关于种群和物种的叙述不正确的是（）
