Explanation

Entomology is the study of insects and their relationship to humans, the environment, and other organisms.

while

Zoology is the study of all animals.

Biology is a natural science concerned with the study of life and living organisms.

Etymology investigates and documents the lives.

Explanation

Lactometer is used for milk

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A lactometer is an instrument that is used to check for the purity of milk by measuring its density.

 lactometer works on the principle of gravity of milk.

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Explanation

When using "Neither...nor," the verb agrees with the noun closest to it.

"Friends" is plural, so the correct verb is "were."

Explanation

This idiom is used when someone you've just been talking about appears unexpectedly.

It's often said in a light or humorous tone.

Explanation

Happy means خوش

Hapless means بے بس

Unlucky means بد قسمت

Lucky means خوش قسمت 

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Explanation

Species is the basic unit of classification.

Species are a group of organisms that are morphologically similar and can interbreed.

1. Kingdom
2. Phylum
3. Class
4. Order
5. Family
6. Genus 
7. Species

Explanation

A hypothesis is a tentative statement or prediction that can be tested through scientific investigation.

It must be subjected to experimentation or observation to determine its validity — it is not always proved but always tested.

Explanation

Inverse Proportion:

When one quantity increases, the other decreases in such a way that their product remains constant.

Example: Speed increases → Time to cover the same distance decreases.

Direct Proportion:

When one quantity increases, the other also increases at the same rate.

Example: More hours worked → More wages earned.

Explanation

Cations are positively charged ions. 

Cations are formed when a metal loses its electrons.

Explanation

Let's denote the two integers as x and y, where x > y:

Given x - y = 3 and x² + y² = 89.

From x - y = 3, we get x = y + 3.

Substitute x in the second equation:

(y + 3)² + y² = 89

y² + 6y + 9 + y² = 89

2y² + 6y - 80 = 0

y² + 3y - 40 = 0

(y + 8)(y - 5) = 0

y = -8 (not possible since y is positive) or y = 5.

If y = 5, then x = y + 3 = 8.

Check: 8² + 5² = 64 + 25 = 89.

The integers are 8 and 5.