根据硫元素的化合价判断，下列物质中的硫元素不能表现氧化性的是[ ]
A．Na2S
B．S
C．SO2
D．H2SO4
答案：A
Mingming got up very _______,so he came to school half an hour ______.
A．late; lately
B．lately; late
C．lately; lately
D．late; late
十进制数2344用二进制数表示是
A．11100110101
B．100100101000
C．1100011111
D．110101010101
