When I passed this afternoon I saw Mary lying on the grass her handsunder her head.A. ha

问题补充：

When I passed this afternoon ,I saw Mary lying on the grass, her handsunder her head.

A. having crossed

B. crossing

C. crossed

D. to cross

答案：

A. having crossed

B. crossing

C. crossed

D. to cross

解析：独立格结构，cross与her hands 之间构成被动，故用crossed.