52.　　 52.　　 Contrary　 to ______ I had expected, he lost for a second time.

a. that　　 b. what　　 c. which　　 d. who

51.　　 51.　　 Now we may be able to say ______ between music and noise or just sound.

a. what is the difference　　 b. the difference is what

　 c. what the difference is　　 c. that what the difference

50.　　 50.　　 Einstein’s theory of relativity seemed hard to believe at the time ______.

a. when he first introduced　　 b. that he first introduced it

　 c. he first introduced　　　　 d. which he first introduced it

49.　　 49.　　 Group work is a method of teaching ______ tasks and activities are carried out by small groups of pupils.

a. which　　 b. that　　 c. for which　　 d. in that

48.　　 48.　　 The rose may grow as a low bush or as a tree, depending on ______.

a. what it is trimmed　　 b. how it trimmed　　 c. that is trimmed　　 d. how it is trimmed

47.　　 47.　　 ______ you return those books to the library immediately you will have to pay a fine.

a. Until　　 b. If　 　c. Unless　　 d. Provided

46.　　 46.　　 He went to work so late ______ the manager had to send for him again before he arrived.

a. as　　 b. that　　 c. for　　 d. when

45.　　 45.　　 ______ difficulties we may come across, we will help one another to get over them.

a. Whatever　　 b. Whichever　　 c. However　　 d. What

44.　　 44.　　 ______ the world began, nations have had difficulty in keeping peace with their neighbors.

a. Although　　 b. When　　 c. Until　　 d. Ever since

43.　　 43.　　 The first step in preparing such a program is to draw a flow chart, ______ are shown opposite.

a. two examples of it　　 b. two examples of which

c. whose two example　 d. which two examples