下图人物提出了
A．地心说
B．日心说
C．大陆漂移说
D．板块构造学说
答案：C
All the scientific evidence ________ that increasing use of chemicals in farming ________ damaging
our health. [ ]
A . show; are
B. shows; are
C. show; is
D. shows; is
函数f(x)=x|x+a|+b是奇函数的充要条件是（）。
A．ab=0
B．a+b=0
C．a=b
D．a2+b2=0
