—The boys hid themselves in the places ________ they couldn’t be found.

—How naughty(淘气的) they are!

A．that

B．which

C．where

D．in that

已知等腰三角形的两边分别为3cm和7cm，则其周长等于（　　）

A．13cm

B．17cm

C．13cm或17cm

D．10cm