side-kick 莫逆之交

sign up for 报名参加

sink in the scale 降低

sitting pretty 过着舒服的生活

sixes and sevens 乱七八糟

sixth sense 第六感

size up 打量

sleep in this morning 睡个懒觉

slip one's memory 一时忘记

slow-poke 行动迟缓的人

slowly but surely 稳扎稳打

small potato 小人物

smoke like a chimney 烟鬼

smoke O.P.B 吸别人的烟

snake in the grass 隐藏的危险

snap out of it 突然改变情绪；振作起来

Snowed. （学生）被一个问题弄糊涂。

so that's it 原来如此

So what？ 那又怎么样？

soft-soap 谄媚

somehow or other 莫名其妙地

sore spot 伤心事，旧疮疤

Sorry to have kept you waiting. 抱歉，让您久等了。

sounds just like 看样子就象

speak of the devil 说曹操曹操到

speak the same language 志同道合