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( }. Q# N' Y% `/ {shall 应 指满足本规范必须遵从的强制性要求
" W% G( W: v& [should 应该 指在多个可能性当中,认为特别合适,但不排斥其它的可能性.或是优选一套措施,但不是要求.或是
/ Z) _& v, r- D7 E在否定证据当中不赞成某个措施但也不禁止
$ x# G8 o* {% U7 `建议看一下:6 A9 s( q" ~. E) {, f
http://bbs.angui.org/forum.php?m ... ghlight=shall%2Bmay1 Z. N8 d8 s Z {7 }' G. S3 o
如果可以用别的颜色作为地线,那么,不排除让写标准的人承认,“棕、蓝”都可以用来作地线
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; w+ Y4 F* ]7 {5 u9 c1 b' S7 i# Esingle-core cable: no preferred colour scheme;$ Y+ P6 m" z# ~/ ]
two-core cable: no preferred colour scheme;
- S6 c I# U) ^three-core cable: either green-and-yellow, blue, brown,
, t+ A# Y& ^( Aor brown, black, grey
$ w0 z b0 t/ @6 ? I m+ @four-core cable: either green-and-yellow, brown, black, grey,# e8 [1 t. q: L) U6 x) `
or blue, brown, black, grey* z/ |4 s1 `* T% j) A, A, h$ j
five-core cable: either green-and-yellow, blue, brown, black, grey,7 ], D2 Z" z' m% N0 Y9 ^1 p2 @
or blue, brown, black, grey, black.
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