discard: implies the letting go or throwing away of something that has become useless or superfluous though often not intrinsically valueless: ~ any clothes you are unlikely to wear again.


cast: especially when used with off, away, and out, implies a forceful rejection or repudiation: ~ off her friends when they grew tiresome.   （原文forceful表示坚决而不是强迫用力，cast表示丢掉的东西轻，所以强迫用力讲不通）


shed: refers to the seasonal or periodic casting of natural parts, such as antlers, hair, skin, or leaves, and to the discarding of whatever has become burdensome or uncomfortable: ~ her tight shoes at the first opportunity.


slough: implies the shedding of tissue, as from a scar or wound, or the discarding of what has become objectionable or useless: finally ~ed off her air of jaded worldliness.   (worldliness世俗，即投身现世的事业和生活) (jaded: 因为疲劳而厌倦，参见疲劳tire-fag组)


scrap: suggests a throwing away or breaking up as worthless but implies the possibility of salvage or further utility: all the old ideas of warfare had to be ~ped.


junk: is close to scrap but tends to stress finality in disposal: those who would ~ our entire educational system.


discard丢弃: 丢弃无用多余的东西，可能有价值，cast抛弃: 和off, away, out连用，表示坚决抛弃不再承认，shed脱落: 季节周期性的自然脱落如角发肤叶，或负担累赘(burden,uncomfort)，slough也是脱落: 但表示伤口疤痕，或无用又讨厌的东西，scrap丢弃: 认为无用而丢弃，但可能将来回收利用(salvage废料回收，抢救的财产)，junk彻底丢弃: 强调最终


记忆方法: 1) 首字母DCSSSJ重组成SCSDSJ时常使的手机<==丢弃

         2) 丢弃的意思是认为没有使用价值而排除掉mean to get rid of as of no further use, value, or service.首字母DCSSSJ重组成SCSDSJ时常使的手机<==丢弃