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

42.　　 42.　　 ______ Ms. Wang reached the post-office, she discovered she had left the letter at home.

a. Just as　　 b. Because　 　c. As long as　　 d. When as

41.　　 41.　　 The chairman of the union made it clear at the meeting ______ he would not step down form his position as chairman.

a. in which　　 b. where　　 c. because　　 d. that

40.　　 40.　　 Fox was advised to give the assignment to _______ he believed had a strong sense of responsibility.

a. whom　　 b. whomever　　 c. whoever　　 d. that

39.　　 39.　　 Advertising is distinguished from other forms of communication ______ the advertiser pays for the message to be delivered.

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

38.　　 38.　　 He gave ______ came to the store a pamphlet in which his products were described.

a. who　　 b. those　　 c. whom　　 d. whoever