A horse may stumble on four legs.马有四条腿,亦有失蹄时.I walked up one road , down another , expecting to stumble on something recognizable.我东投西奔, 指望撞见认得的东西.I make it into the darkness with only one stumble.我只是绊了一下，周围就变成了一片黑暗。If y...
All forms of reciprocal theorems apply to structures which behave linearly.所有形式的互等定理都适用于线性受力状态的结构.His doctoral dissertation on differential equations connected itself with existence theorems.他论述微分方程的博士论文涉及到存在理论.The three...