几个英语问题This ,of course,will lead to_______in speaking style.A

几个英语问题
This ,of course,will lead to_______in speaking style.
A.some change
B.certain change
C.a great deal of changes
D.a lot of change
我选了d,可是答案是A
The area where the greatest change has been taking place is_____of vocabulary.
A.one
B.that
C.it
D.every
They didn't inform us of________they called the newly-built company.
A.that
B.what
C.when
D.why
第2题解释下