2.

23 12- 14 17=895=5* 179

23 12- 1059= 1253=7* 179

14 17- 1059=358=2* 179

The divisor of * * is only 179, and x is 197.

The remainder is:1059/179 = 5 ...164.

179- 164= 15

The answer is B.

3.

Let n 3+100 = k (n+10)

Because n is a positive integer and k is a positive integer.

(n^3+ 100)/(n+ 10)=k

(n^3+ 1000)/(n+ 10)-900/(n+ 10)=k

(n^2- 10n+ 100)-900/(n+ 10)=k

(n 2-10n+100) is a positive integer,

So let k be a positive integer.

Then 900/(n+ 100) is required to be an integer.

So n can reach 890.

At least 2

4. Write down the natural number 1, 2, 3, ... to form a number:1234567891011213 ...

Solution: 72=8×9, which means that this number is an even number divisible by 9, the last three digits are multiples of 8, and the last two digits are multiples of 4.

At 123456789. 456 is a multiple of 8, but 123456 is not a multiple of 9;

101121314 161718,/kloc-0. It is (1+2+3+4+5+6+7+8+9)+(1+0)+(1+)+(1+2) = 5655.

In 202 12223242526272829, the multiple of 4 is 20, 24, 28, of which 920,728 is a multiple of 8, but (1+23+... 9)+(1+65438+)

In 303 13233343536373839, the multiple of 4 is 32,36, of which 536 is the multiple of 8, (1+1+65438+1+2+...+65433.

So when writing the natural number 36, you can divide the long number by 8 and 9 at the same time for the first time.

A: This natural number is 36.