arrear
n. 待完成的工作，职责；欠款；在后面的事物
例句
He is six week In arrear with his rent.
他拖欠了六个星期的租金。
He is six weeks in arrear with his rent.
The arts of medicine and surgery are somewhat in arrear in Africa.
医疗和外科手术在非洲稍微有些落后。
