题目

 Li Yang, the founder of Crazy English, says that he copies it down _______ he comes to a sentence. A. unless                  B. while                   C. because             D. every, time 答案：D在火箭竖直向上加速运动的过程中，座椅对宇航员的支持力           （选填“大于”或“小于”）宇航员的重力，宇航员处于          （选填“超重”或“失重”）状态。