contract: applies to a drawing together of surfaces or particles or a reduction of area, volume, or length: caused his muscles to ~.


shrink: implies a contracting or a loss of material and stresses a falling short of original dimensions: the sweater will ~ if washed improperly.


condense: implies a reducing of something homogeneous to greater compactness without significant loss of content: ~ an essay into a single paragraph.    (homogeneous均匀的同质的，如homogeneous rock质地均匀岩石，a homogeneous population单一民族人口)


compress: implies an pressing into a small compass and definite shape, usually against resistance:  ~ed the comforter to fit the box.     (compass小范围: within the compass of a book在一本书的篇幅范围内，还表示指南针圆规)


constrict: implies a narrowing by contracting or squeezing: the throat is ~ed by too tight a collar.     (squeeze挤压: to press firmly用力压挤压, 如to squeeze a tube of toothpaste挤牙膏)


deflate: implies a contracting by reducing the internal pressure of a contained substance and stresses the limp or empty state that results: ~ his tires to get better traction.       (traction牵引力，tract词根表示牵引，如tractor拖拉机contract收缩retract收回指责或诺言)


contract收缩: 表面微粒收到一起(draw together,draw吸引吸收)体面长减少，shrink也是收缩: 用于收缩或减少，强调比最初尺寸小，condense浓缩: 使紧缩(compact)但保留内容，compress压缩: 克服抵抗，将范围压小，constrict紧缩: 指通过挤压使变窄，deflate放气: 通过减少内部物质压力使收缩，导致空虚垂软状态


记忆方法: 1) 首字母CSCCCD想成常常常常的事<==膨胀和收缩都是物质常态

              2) 收缩的意思是体积变小mean to decrease in bulk or volume.首字母CSCCCD想成常常常常的事<==膨胀和收缩都是物质常态      (bulk固体体积，如bulk of skyscrapers大楼，volume流体体积，如volume of water大量的水)