2. Multiply the upper and lower parts by 2-i and then simplify to make the real part negative and the imaginary part positive to get the same result as A.

3. Divide the number of rainy days by the total number of days to get the 5/20 option B.

4. Set the height to a and write the volume formula. As long as a is solved, the calculated area is 6√3. Choose a.

The n power of 5.2 is equal to 256, and the solution is n=8. Then, according to the binomial theorem, 256 choices d are obtained by multiplying the combined number C8 2 by the square of 3.

6. expressed by k, two inequalities are obtained. Then the solution is (56, 72 choose B.

7. Divide the integral area from 1/2 to 1 by 2 to get c.

8. According to the former condition, p 1p2 is on the same side of the straight line. According to the second condition, the distance from p 1 to L is shorter than p2, so B is chosen.

9. When 9. AB is perpendicular to the x axis, and the maximum ratio is a.

10. This is a complex function problem, and there are two solutions, one is the mirror image method, and the other is the point-by-point method. choose one

1 1. According to the characteristics of the average value of the average value Y of the straight line crossing X, t is used to represent the average value of Y, and the average value of X is 5, so that t=50 is obtained.

The ordinate of 12. OA is 4cosαsinα, that is, 2sin2α. According to the angle range, 1, 2 is obtained.

13. It is not difficult to calculate that △OAB is a regular triangle with a side length of 2, so according to S= 1/3* base area * height is 4√3/3.

14. The special value method makes c=√5 b= 1 a=- 1 to get (√5- 1)/2. Similarly, because A B C is uncertain, there is (-√5- 1)/2.

Choosing examination questions is very simple, so I won't say it. If there is anything not, you can ask.

thank you