两台同型号水泵串联相接时，其流量与原一台水泵相比（）
A、增大
B、减少
C、不变
参考答案：C
Owing to environment pollution, a number of insects have ________. [ ]
A. died out
B. put out
C. brought out
D. picked out
A．FDDI
B．剑桥环网
C．ATM局域网
D．以太网
