lacuna的复数形式怎么写？

Reasons of forming first cracks were foundry lacuna, impurity gathering , lard exiting.铸造缺陷 、 杂质元素偏聚和夹杂物的存在是形成早期裂纹源的原因.There was so much very deep lacuna in his crude big hands.粗糙的大手上一道道很深的裂口.Objective To investigate the...

lacuna的音标：lacuna的英式发音音标为：[lə'kju:nə]lacuna的美式发音音标为：[lə'kjunə]...

n.空白，空隙，腔隙，缺陷...