慢性肾衰初期以哪个系统的症状为主
A．血液系统
B．消化系统
C．呼吸系统
D．循环系统
E．神经系统
参考答案：B
国内外大量主观评价的调查结果表明，噪声超过( )，人们感到吵闹。
A．50 dB
B．70 dB
C．55 dB
D．60 dB
Some children were skating on the ice happily. Suddenly one of them ____ the water and the other children
felt ____. [ ]
A. falls into; mad
B. fell into; frightened
C. fall into; mad
D. felt into; frightened
