455．After two year's research,we now have a _____ better understanding of the diease.
A.very
B.far
C.fairly
D.quite
456.Alan is a careful driver,but he drives _____ of my friends.
A.more carefully
B.the most carefully
C.less carefully
D.the least carefully
455.答案是B;far,rather,much,any,no等修饰比较级。
456.答案是D;由of my friends得知应用较高级，而but表示转折。
