51._______ 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
52.It rained hard yesterday， ______ prevented me from going to the park.
A. that B. which C. as D. it
53.When _______， water will be turned into steam.
A. heated B. heating C. being heat D. having heated
54.Please write a report _______ the above subjects are to be covered.
A. which B. in which C. that D. in that
55.This is the most beautiful village _______ I visited these years.
A. which B. where C. in which D. that
56._______， could you get me a Turkish conversation book?
A. In this way B. By the way C. In no way D. In any way
57.Such person _______ you describe is rare nowadays.
A.it B.as C.that D.what
58.The oceans do not so much divide the world _______ unite it.
A. as B. that C. but D. like
59.He found _______ difficult to study maths.
A. it B. that C. as D. too
60.I understood from her that you undertook other important work ______.
A. as well B. as too as C. as also as D. as good as
