石墨炉原子吸收分析阶段，灰化的含义在于（）和（）的灰化清除，保留分析元素。
参考答案：基体；干扰物
For the sake of your health, I’d rather you ___ a flat in the mountain than ___ in downtown area as the transport is getting more convenient.
A．bought, one
B．to buy, that
C．bought, the one
D．to buy, what
图纸未注明钢筋搭接长度时，受压钢筋搭接长度取收拉钢筋搭接长度的( )倍。
A．0.8
B．0.7
C．0.65
D．0.6
