si 17造句

例句与造句

1. They all share the same basic formula : ( Na 2, Ca, Mg ) 3.5 [ Al 7 Si 17 O 48 ] ?2 ( H 2 O ) by varying the amounts of sodium, magnesium and calcium.
2. It's difficult to find si 17 in a sentence. 用si 17造句挺难的