急性出血坏死型胰腺炎的主要表现为( )
A．持续腹痛B．酗酒C．低血糖D．胆道疾患E．休克
参考答案：E
(2009浙江宁波质检)Since David ________ downloaded a virus into his computer, he can not open the file now．
A．readily
B．accidentally
C．horribly
D．irregularly
设f(x)在[-π，π]上连续，且有
，求f(x)．
，求f(x)．