-- It is reported that many wild animals in the world are _______ because of human behavior.
-- We must do something to stop people from hunting and selling these animals.
A:in danger
B:in public
C:in silence
人耳的听觉范围是____至____,频率高于____的声音叫做超声波,频率低于____的声音叫做次声.
如图,∠A与____ 是内错角,∠B的同位角是____ ,直线AB和CE被直线BC所截得到的同旁内角是____ .