2 popular - unpopular
3 common - rare
4 important - unimportant
5 to receive - to give
6 narrow - broad
7 to contruct - to destroy
8 free
指東西很空閑的時候:FULL(充滿)
指人很空閑的時候:BUSY(繁忙)
作自由講，Durance
9 to flourish - to decay
10 silently - noisily
11 alone - together
12 gentle - harsh
13 obviously - indistinctly
14 reluctantly - willingly
15 practical - theoretical
16 satisfaction