Be lack of 和 lack
在一本书上看到lack作为动词和名词时的不同用法...
它引用一个错误的例子是
Many students are lack of independent learning skills because the education system spoon-feeds them.
我想问问如果改成这样行不行:
Many students lack independent learning skills because the education system spoon-feeds them.
如果行,究竟为甚麼必须用lack,而不能用be lack of?