a，b为有理数，下列式子成立的是[ ]
A．|a|=a
B．a3=（﹣a）3
C．3a>2a
D．a2+1≥1
答案：D
It made all the Chinese happy _____ China succeeded in sending up the first manned spaceship.
A．when
B．because
C．that
D．if
肾毒物可引起（）
A.肾前性急性肾衰竭
B.肾性急性肾衰竭
C.肾后性急性肾衰竭
D.慢性肾衰竭
E.尿崩症
