若a2=25，|b|=3，则a+b等于[ ]
A.-8
B.±8
C.±2
D.±8或±2
答案：D
Can you think of a situation ______people communicate only by meansof bodylanguage?
Can you think of a situation ______people communicate only by means
of
body
language?
A．that
B．which
C．where
D．when
液压系统缸体磨损严重时可采用（）修复。
A.铅焊
B.焊接
C.研磨
