考研必备：考研写作1500词

　　Common Prefixes

　　dis - not

　　pro - for, supporting

　　re - to do again

　　self - used to show that the person or group acting is the one affected by the action, or to show that the action is done only by its own effort or power

　　un - not

　　Common Expressions

　　carry out - to do; to put into effect

　　pass a bill - approve

　　take steps - to start to do something