overburden的一般过去时怎么拼写？

overburden的音标：overburden的英式发音音标为：[ˌəʊvə'bɜ:dn]overburden的美式发音音标为：[ˌoʊvər'bɜrdn]...

vt.装载过多，负担过多，使过劳n.过重的负担...

Overburden had concealed the radioactivity.覆盖层屏蔽掉了放射性.Soil survey should be adopted in such soil overburden areas.在此类土壤覆盖区应采用土壤测量.Overburden pressure for three hundred years , isolated the light of day.覆压三百余里, 隔离天日....

overburden的第三人称单数（三单）为：overburdens...

overburden的现在进行时为：overburdening...

overburden的现在完成时为：overburdened...