骨折复位的最佳时间是伤后______之内，一般成人伤后______内可考虑手法复位，但时间越久复位困难越大。
参考答案：半小时 7～10天
已知M2O7x－+3S2－+14H+ =2M3++3S↓+7H2O,则M2O7x－中的M的化合价为（ ）
A．+2
B．+3
C．+4
D．+6
Many political leaders attended the conference and among those present ____ the foreign minister and his wife.
A．were
B．included
C．had
D．remained
