参考答案

正确答案：D
解析：此题考查动词词组的辨析。hold down意思是“压制，抑制”，在此句中是“抑制”的意思。hold up意思是“举起，支撑，阻挡，拦截”，如：Most of the lower class people in big cities are simply trying to hold up under the daily stress．hold off意思是“不接近，拖延，不使接近”，如：The board of directors will hold off making a decision until