题目

 They became good friends during the war, and since then their lifelong friendship has______ tests of life and death.    A. got through              B. gone through    C. stood up                      D. cleared up 答案：B20．变形虫是常见的单细胞生物，它的（　　）不仅具有运动功能，还具有围住食物完成摄食的作用．A．食物泡B．伪足C．伸缩泡D．细胞膜