At last we found ourselves at the foot of a hill with trees providing shade and down to

问题补充：

At last, we found ourselves at the foot of a hill with trees providing shade and down to eat our picnic lunch.

A. sitting

B. having sat

C. to sit

D. sat

答案：

A. sitting

B. having sat

C. to sit

(答案→)D. sat

解析：答案：D考查对动词形式的理解。sit与found是并列谓语。