Old ________ Dr Wang is, he often works with us from morning till night.

Old ________ Dr Wang is, he often works with us from morning till night.

A.although

B.even though

C.as if

D.as

答案及解析： D

解析：

as引导的让步状语从句采用半倒装，表语或状语提前。其他三项无此用法。