—Will you play basketball against Class 3 tomorrow?—Yesit snows.A. IfB. UntilC. WhenD.

问题补充：

—Will you play basketball against Class 3 tomorrow?

—Yes. it snows.

A. If

B. Until

C. When

D. Unless

答案：

A. If

B. Until

C. When

(答案→)D. Unless

解析：考查连词。根据语境是除非下雪才不去打篮球。