The answers :
1-C
2- C
3- B
4- A
5- D
6- D
7- A (not sure!)
8- C
9- B
10- B
11- A
12- C (not sure of question)
13- not clear!!
14- B
15- C
16- D
18- A
19- C (not sure! Maybe A)
20- A
21- C
22- A
23- D
?...
29- )abab cdcd
30- D
31- A
32- A
33- B
34- A
35- C
36- D
37- D
38- A
39- A
40- A
41- C
42- C
43- C
44- C
45- C
46- B
47- D
48- C
49- C