下列哪种物质对胆碱酯酶的合成有影响
A．汞
B．铅
C．砷
D．有机磷
E．锰
参考答案：E
下列的哪个赋值语句是不正确的
A．float f = 11.1；
B．double d = 5.3E12；
C．float d=3.14f；
D．double f = 11.1E10f；
—Are there _______ giraffes in the zoo?
—No, there aren't _______. [ ]
A. any; some
B. any; any
C. some; any
D. some; some
