重点讲解：
1. up one's sleeve
藏有…想法；留有锦囊妙计；心中另有…高招；
eg. He wondered what Shearson had up his sleeve.
他暗自猜度希尔森究竟有什么高招BBMtBEaA81awR。
eg. I'd been doing some quiet investigating in the meantime and had an ace up my sleeve.
与此同时，我不动声色地展开了调查，掌握了一张王牌v~iIDos_351)r。
2. for sure
无疑；肯定；
eg. You'll have it for sure by the end of the week.
这个周末你一定能收到它的y-S(0vh2NU3l2l_Qsz。
eg. For sure today was a not great day for us.
当然今天对我们来说不是非常好的一天Kqo5^!F+qvp~y!e^。
3. feel free
请随意；不必拘谨；
eg. Go right ahead. Feel free.
开始吧(jCDe_*AF%^F。请便AxX9)~nyz-|。
eg. If you have any questions at all, please feel free to ask me.
如果有任何问题，请随意提问qQvqO2KIVPi6@)t。