091. drop by /in 顺便走访
EG: Would you drop in on me /at my
house this evening?
092. drop off
[1]减弱，减少；
[2]打瞌睡；=doze off
093. drop out
[1]退出，离队；
[2]不参与，弃权。
094. dwell on /upon
[1]深思熟虑，再三考虑；
[2]详述。
095. embark on /upon 从事，着手，开始工作
    EG: China embarked on a massive programme of reform. 中国开始实施大规模的改革计划。
096. face up to 大胆面向
EG: He has never been able to face up to
the realities. 他从来都不能大胆面对现实。
097. fail to  未能
098. fall back on 转而依靠，求助于
099. fall behind
[1]落后；
[2]（付款等）逾期。
100. fall in love (with) 相爱，爱上
EG: I fell in love with her at first sight.
我对她一见钟情。
101. fall in with
[1]符合，与…一致；
[2]碰见（偶然）。
102. fall out
[1]争吵，争执；
[2]发生，变成…（的结果），结果是；
[3]（军）离开队伍。
103. fall through 落空，失败
104. feed in 输入
EG: You feed in coin here and the coffee comes out there.
105. feel like (doing) 欲，想要，[一般用于否定句或疑问句中]
EG: I don’t feel like eating now.