the surface soil that must be moved away to get at coal seams and mineral deposits
an excessive burden
Verb
burden with too much work or responsibility
load with excessive weight
例句
用作动词(v.)
The education system rather than the teachers is to answer for overburden on the students .使学生负担过重的是教育体系而不是老师。
Because of the overburden of our commitments, we are unable to ship your order within the agreed period.由于我方订货负担过重，无法在协议期限内交货。
Language teachers should be aware of the priority in vocabulary instruction and had better not overburden students' memory.首先词汇教学的内容要重点突出，循序渐进，不能使短时记忆超负荷。
