11._______ is known to all，China will be an _______ powerful country in 20 or 30 years‘ time.
A.That;advancing
B.This;advanced
C.As;advanced
D.It;advancing
12.It rained hard yesterday， ______ prevented me from going to the park.
A. that
B. which
C. as
D. it
13.When _______， water will be turned into steam.
A. heated
B. heating
C. being heat
D. having heated
14.Please write a report _______ the above subjects are to be covered.
A. which
B. in which
C. that
D. in that
15.This is the most beautiful village _______ I visited these years.
A. which
B. where
C. in which
D. that