Therootsofthesevegetablesarenotplantedinearthbuthanginwaterthatcantainsallthenutrientstheyneedtogrow.本句中“allthenutrientstheyneed”是否是定语从句,而“togrow”只是做目的状语,还是“togrow”与“

　　Therootsofthesevegetablesarenotplantedinearthbuthanginwaterthatcantainsallthenutrientstheyneedtogrow.

　　本句中“allthenutrientstheyneed”是否是定语从句,而“togrow”只是做目的状语,还是“togrow”与“allthenutrientstheyneed”合起来,即“allthenutrientstheyneedtogrow”作定语从句?另外togrow是不是做目的状语我不肯定,

　　cantains前面是一个定语从句，但是后面allthenutrientstheyneedtogrow又是一个定语从句，若togrow与allthenutrientsthattheyneed合起来是定语从句，即allthenutrientsthattheyneedtogrow是定语从句，那么that代替先行词allthenutrients在句中做什么成分？