英语好的童鞋,麻烦帮我分析下这些句子的结构及成分,

For example是插入语,a chemical是主语,approved for use on lettuce是后置定语,修辞主语的 would be considered in violation,是谓语 if used on cabbage or any other food是条件状语.Unfortunately是插入语,tolerances主语 are是系动词frequently程度副词 sources of consumer concern是表语 when they are misinterpreted to mean the levels of residue时间状语 that may be expected in the marketplace定语从句,先行词是residue,在定语从句中做主语.

例如，一个化学批准用于生菜会如果用白菜或任何其他违反食品在考虑。不幸的是，公差经常消费者关心的来源，当他们误解的意思，残留的水平，可以预期在市场上。