x2-8x+（ ）=（ ）2；9x2+12x+（ ）=（ ）2。
16，x+4；4，3x+2
改错，下面每句话均有一处错误，请选出来，并在横线上改正。
( ) 1. Look on this postcard. ______________
A B C D
( ) 2. I want send this postcard to my mother. ______________
( ) 3. How much on this postcard? ______________
继发性胆脂瘤多发生于
A．鼓窦入口B．外耳道C．上鼓室D．中鼓室E．下鼓室
