34=9÷12=912=1216=0.75．
故答案为：9，9，16，0.75．
While building a tunnel through the mountains, ______.
A．an underground lake was discovered
B．there was an underground lake discovered
C．a lake was discovered underground
D．the workers discovered an underground lake
电源电压不变，在电路中再串联一个3Ω的电阻时，电流变为原来的5/6，则电路中原有的电阻是______Ω．
