37. This is one of the means ______ the electric energy is conducted from one place to another.
A. by which B. by that
C. through which D. through that
36. In the dark street, there wasn’t a single person ______ she could turn for help.
A. that B. who C. from whom D. to whom
35. She heard a terrible noise, ______ brought her heart into her mouth.
A. it B. which C. this D. that
34. He paid the boy 10 dollars for washing ten windows, most of ______ had not been cleaned for years.
A. these B. those C. that D. which
33. All ______ is needed is a supply of oil.
A. the thing B. that C. what D. which
32. The buses,__were already full, were surrounded by an angry crowd.
A.most of them B. most of which
C. which most D. that most
31. ______ is natural, he married Mary.
A. It B. What C. Which D. As
30. His father died last year, ______ made it impossible for him to go abroad.
A. when B. which C. as D. that
29. He must be from Africa, ______ can be seen from his skin.
A. that B. as C. it D. what
28. The reason ______ he didn’t come was __ he was injured.
A.that, because B. why, that
C.why, because D. that, that