2010四六遥备考：阅读真题常见的短语(15)　　211.
be on duty值班，值日，在上班时 　　212.
be in duty bound to(do)(=be required by ones job or esp.
by conscience)有义务(做) 　　213.
be eager for想得到，盼望 　　214.
by ear(=play music from memory without having seen it printed)凭记忆，不看乐谱 　　215.
have an ear for(=have keen recognition of sounds esp.
in music and language)对有鉴赏力 　　216.
a word in ones ear私房话，秘密话 　　217.
on earth究竟，到底，全然 　　218.
with ease(= easily)容易，不费力 　　219.
at(ones)ease(= without worry or nervousness)自在，不拘束 　　220.
put sb.
at his / her ease(=free sb.
from worry or nervousness)使某人感到无拘束 　　221.
economize on(=save sth.
instead of being wasteful)节省 　　222.
have an effect on对有影响 　　223.
be in effect(=be in operation)遥 　　224.
go into effect生效(近：come into effect;take effect;be brought into effect) 　　225.
in effect(=in fact，really)实际上