如何使用LINQ在foreach命令中插入多行？

I wrote these lines:

我写了这些文字:

foreach (var catId in CatIds)
{
    AdCategory.AdId = LastAd.AdID;
    AdCategory.CategoryId = catId;
    EngineDB.Ad_Categories.InsertOnSubmit(AdCategory);
    EngineDB.SubmitChanges();
}
foreach (var