分类：教育/科学-学习帮助
问题：19.Asamother,Iseldomgivemychildr? 
19. As a mother, I seldom give my children so difficult a job _____they can’t do actively.        A. that    B. as      . which    D.what 
回答：此题选B，引导一个定语从句。
当先行词前是so，as，such时，关系代词用as