题目

Fortunately, the little girl ________ in the air-crash, but unluckily, the others on the flight were killed. A. was survived      B. has been survived C. was surviving     D. survived   答案：D  考查时态。根据上下文可知是对过去事件的描述，故用一般过去时。  如图所示，质量均匀的物体悬浮在水中，现将它沿图示虚线切为大小不等的两块后仍放在水中，则（ ）A．大块下沉，小块上浮B．大块悬浮，小块上浮C．两块都悬浮D．两块都下沉