they are twin brothers they don’t look like each other.A. ThoughB. SinceC. HoweverD. Whe

问题补充：

they are twin brothers, they don’t look like each other.

A. Though

B. Since

C. However

D. When

答案：

(答案→)A. Though

B. Since

C. However

D. When

解析：本题的含义是虽然他们是双胞胎，但他们看起来不像，though引导让步状语从句，符合本题，故本题选A。