Divide two rational numbers that are not zero. If the positions of dividend and divisor are reversed and the quotient remains the same, then these two numbers must be (d).

Equality; (b) reciprocity.

Equivalent or equivalent.

20. Add "+"or "-"... 99, 1 00 to the number 100 of13, and the result must be (d).

(a) Odd (b) Even (C) 0 (D) Uncertain

The integer digits of the number1.001×1025 expressed by scientific notation are (c).

(A) 23 bits (B) 24 bits (C) 25 bits (D) 26 bits

Use the calculator and follow the flow chart as shown in the figure:

(1) If the positive odd number input for the first time is 1 1, the change process can be expressed as:11→17 →13→ 5 →/kloc-. When the positive and odd numbers input for the first time are 9 19, please use a similar method to show the changing process of the operation according to the flow chart;

(2) Select several positive and odd numbers and write down the change process according to the flow chart to see if there will be the same result;

(3) According to the result of your operation, give a guess and clearly state your guess.