6.＿＿＿ can we be sure of making much progress in English.
(A)By doing only practice
(B)If writing more exercises
(C)Having more exercises
(D)Only by having more practices
(E)By only doing more practices
12.The first thing which a student should bear in mind is that a book ＿＿＿ for mere amusement.
(A)ought to not be read
(B)not ought to be read
(C)ought to be not read
(D)ought not to be read
(E)ought not read