⑴You need a swimming cap. ____
⑵First,you should wash yourself. ____
⑶Next,you should do warm-up exercises. ____
⑷Then, you can enjoy your swimming lessons. ____
⑸You need a swimsuit.____
A. B. C. D. E.
如图,正方体的棱长为5,一只蚂蚁如果要沿着正方体的表面从点A爬到点B,需要爬行的最短距离是____
设fx是定义在R上的奇函数,且当x≥0时,fx=x2.若对任意的x∈a,a+2,不等式fx+a≥f2x恒成立,则实数a的取值范围是( )