When deeply absorbed in work, _____ he often was, he would forget all about eating or sleeping.

A．that

B．which

C．where

D．when

国外购进商品的进货成本是进口商品在到达（）发生的各种支出：

A.目的港口以前

B.目的港口以后

C.离岸港口以前

D.离岸港口以后