You’ll find it hard to get rid of the drug habit you have it.A. before B. once C. until D.

问题补充：

You’ll find it hard to get rid of the drug habit you have it.

A. before

B. once

C. until

D. though

答案：

A. before

(答案→)B. once

C. until

D. though

解析：考查连词，before 在什么之前，once 一旦，until 一旦，though 虽然，句意：你会发现出去吸毒的习惯很难一旦你染上。所以选B。