The MPAA is a US film-industry group.

The MPAA美國電影協會 is是 a US film-industry group一個美國電影產業的組織。

For ordinary people, its famous job was giving American films an age rating, so parents could see how much sex, violence, or strong language was in a picture. The letter codes you still meet are G (anyone), PG (a parent may want to sit with a child), PG-13, R (under 17 needs an adult in the cinema), and NC-17 (adults only).

For ordinary people對一般人來說， its famous job was它最有名的工作就是 giving American films an age rating幫美國電影分級， so parents could see這樣家長就能知道 how much sex, violence, or strong language was in a picture一部電影裡有多少性、暴力或粗俗語言。 The letter codes you still meet are你現在還會看到的字母代碼有 G (anyone)G（任何人都可以看）、 PG (a parent may want to sit with a child)PG（家長可能會想陪小孩一起看）、 PG-13PG-13、 R (under 17 needs an adult in the cinema)R（17歲以下要有大人陪同進戲院）、 and NC-17 (adults only)和NC-17（只限成人）。

Older books still mention an “X” rating; though actually the US stopped using X and moved to NC-17, because X had become a porn-shop label. The group later shortened its name to MPA, but many people still say MPAA.

Older books still mention an “X” rating比較舊的書還會提到「X級」； though actually不過實際上， the US stopped using X美國已經不用X級了， and moved to NC-17改用NC-17， because X had become a porn-shop label因為X後來變成色情片專用的標籤。 The group later shortened its name to MPA後來這個組織把名字縮短成MPA， but many people still say MPAA但很多人還是說MPAA。

They do not, by themselves, stand at the door and stop children — cinemas use the ratings, and in the US this is industry custom, not a government law.

They do not, by themselves, stand at the door and stop children他們自己不會站在門口阻止小孩進場—— cinemas use the ratings是電影院在使用這些分級， and in the US this is industry custom而且在美國這是產業慣例， not a government law不是政府法律。

This is an American system. Taiwan has its own ratings, and the letters do not match one-for-one.

This is an American system這是美國的制度。 Taiwan has its own ratings台灣有自己的分級， and the letters do not match one-for-one而且字母並不是一對一對應的。