18.At first, Tom found it difficult towhat his teachers said in class. A: absorbing B: absorb C: absorbed D: have absorbed

Fill in the blanks according towhat you have learned in the video.Yes-no questions are often used in (1) ________ tone indicating uncertainty, but sometimes they are also used in (2) ________ tone. Besides uncertainty, rising tone indicates (3) ________ and (4) ________.Falling tone are often used in (5) ________ , 6) ordinary ________, indicating (7) ________ and (8) ________.