物流服务项目的特点为( )。
A．开放性
B．常规性
C．创新性
D．重复性
E．独特性
参考答案：A,C,E
漂白精的有效成分是次氯酸钠（NaClO），其中氯元素的化合价为[ ]
A．+7
B．+5
C．+3
D．+1
His efforts to raise money for his program were _______ because no one showed any intention to take a cent out of their pockets.
A．in place
B．in vain
C．in effect
D．in sight
