A./ Choose the word whose main stress is placed differently from the others in each group:

1/ A. headmaster           B. holiday             C. attractive            D. internet

2/ A. matter                B. happen               C. listen                  D. below

3/ A. explain               B. problem             C. study                 D. worry

4/ A. habit              B. become           C. learner               D. mother

5/ A. fifteen             B. fifty                    C. center           D. biggest

6/ A. student              B. member             C. prefer           D. teacher

7/ A. subject               B. hello                   C. teacher         D. thousand

8/ A. lesson                 B. woman               C. repair           D. father

9/ A. above               B. sister                  C. widen           D. very

10/ A. corner          B. answer              C. doctor               D. prepare

B./ 1/ A. people           B. classmate           C. lesson                D. devote

2/ A. background       B. tutor                   C. degree               D. master

3/ A. student               B. career                C. tiny                    D. research

4/ A. passage          B. unit                   C. little                   D. become

5/ A. mother            B. mature               C. sister            D. tragic

6/ A. secondary         B. impossible          C. laboratory     D. conditional

7/ A. November         B. December          C. October        D. January

8/ A. receive               B. private               C. brother         D. children

9/ A. general             B. condition            C. another         D. together

10/ A. position        B. extremely        C. continue             D. difficult

C./ 1/ A. routine          B. arrive                 C. morning             D. prefer

2/ A. dinner                 B. harrow               C. neighbor            D. correct

3/ A. dinner                 B. during                C. although             D. number

4/ A. evening          B. usually             C. afternoon           D. another

5/ A. alarm              B. discuss               C. friendly         D. begin

6/ A. morning             B. repair                 C. happy           D. pupil

7/ A. buffalo               B. exactly               C. tobacco        D. continue

8/ A. minute                B. about                 C. Physics         D. English

9/ A. quarter             B. before                C. partner          D. weather

10/ A. peasant        B. finish                C. compare            D. adverb