The product of any two continuous natural numbers must be () A. Prime B. composite C. odd D. even

The product of any two continuous natural numbers must be () A. Prime B. composite C. odd D. even

There must be an odd number and an even number in two continuous natural numbers. According to the parity of numbers, odd number × even number = even number, so the product of two continuous natural numbers (non-0) must be even number. Therefore, select D

If the sum of any five natural numbers is even, then at least () numbers are even
A. 1B. 2C. 3D. 4

According to the parity of the sum of numbers, if the sum of any five natural numbers is even, then if there are odd numbers in the five natural numbers, the odd numbers must be even, that is, four or two, so there is at least one even number in the five natural numbers

There are three consecutive natural numbers, the smallest number is 15 times, the middle number is 17 times, and the largest number is 19 times
There are three consecutive natural numbers. The smallest number is 15 times, the middle number is 17 times, and the largest number is 19 times. Please write such a group of three consecutive natural numbers?

They can be divided by 15, 17 and 19 respectively