产气法
参考答案：
产气法是基于饲料在体外用瘤胃液消化所产生气体的比率
A person’s wealth is often in inverse proportion to their happiness.
A.equal
B.certain
C.large
D.opposite
丝圈式缺隙保持器常用于
A．个别后牙早失B．下尖牙早失C．多数乳磨牙早失D．恒牙早失E．以上都不是
