407.Must I turn off the gas after cooking?
Of course.You can never be ____ careful with that.
A.enough
B.too
C.so
D.very
408.John is very lazy.He falls ____ behind in his studies.
A.very
B.far
C.more
D.still
407.答案是B;never,not等否定词与too连用,意为:无论…也不过分,表示肯定。
408.答案是B;此题根据语境判断。句意:约翰很懒,在学习上,他远远落后。



