N類
no end of (=very many/much) 很多，大量
O類
P類
1. pay the way for為...鋪平道路
2. pay attention to注意
3. put into effect實(shí)行，生效
4. place (or put，lay) an emphasis on 強(qiáng)調(diào)，把重點(diǎn)放在…上
R類
1. round the clock (=all day and all night，usually without stopping) 晝夜不停地
2. rest room廁所，盥洗室
S類
1. side by side肩并肩，一個(gè)挨一個(gè)
2. step by step逐步