you are always optimistic and self-confident I can't wait to make friends with you.A. Tho

问题补充：

you are always optimistic and self-confident, I can wait to make friends with you.

A. Though

B. Since

C. While

D. So

答案：

A. Though

(答案→)B. Since

C. While

D. So

解析：考查连词。句义：因为你总是乐观自信，所以我迫不及待地和你交朋友。Though，尽管，虽然，since因为由于，while当。。。的时候，尽管，so所以。所以B正确。