Mark the letter A, B, C, or D to indicate the word that differs from the other three in the position of the primary stress in each of the following questions.

A. discussion

B. assistant

C. character

D. expensive

Mark the letter A, B, C, or D to indicate the word that differs from the other three in the position of the primary stress in each of the following questions.

A. erode

B. involve

C. reduce

D. product

Mark the letter A, B, C, or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

A. begged

B. canned

C. booked

D. buttoned

Mark the letter A, B, C, or D to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

A. tangle

B. dangerous

C. battle

D.calculate

Tìm x, biết: a) 22x = 44; b) 42. x  = 84 c) 15x + 5 = 65; d) 2.  x  + 5 = 35 - 10