— Shall Mary come to the concert with us?
-Not_____she has finished her paper.
A.since B.once C.when D.unless
— Shall Mary come to the concert with us?
-Not_____she has finished her paper.
A.since B.once C.when D.unless
D
由句意得知,补全句子应该是Mary does not come to the concert with us unless she has finished her paper.