under the tree was a charming girl aged about seventeen or eighteen.A. SatB. SittingC. To

问题补充：

under the tree was a charming girl aged about seventeen or eighteen.

A. Sat

B. Sitting

C. To sit

D. Sit

答案：

A. Sat

B. Sitting

C. To sit

D. Sit

解析：句意：坐在树下的是一个年龄大约在17或18岁的女孩。这句话是倒装句，提前表语，正常的语序是：Acharming girl aged about seventeen or eighteen was sitting under the tree.所以选B。