First, multiple-choice questions.

1- 12、ABDCD DDABC CA

Second, fill in the blanks.

13- 16 、-240 24 20pai -8

Third, the calculation problem.

17、b=4

18, (1)

(ii)150 degrees

19, (1) 0.648

㈡2.48

20、(I)2- 1/2^(n- 1)

㈡n^2+n+n/2^(n- 1)+ 1/2^(n-2)-4

2 1 、( I)r & gt； sqrt( 15)/2

㈡

Article 22, paragraph 1

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