Sir iam not understanding that all cell are of same size then if all cells are of same size then the shape of some cells are long,wideect then the size of cells are also different.

In our book line is given that

The difference in the size in organism are no of cells present in them not that all animals have different sizes of cells.

Iam confused that all cells are of same size or different sizes. please explain me clearly that i can understand,and please explain in clear and easy wording

I want  complete notes on the chapter friction 

In my book subtopics are:

Friction 

Types of friction 

Factors affecting friction 

Methods of reducing friction 

Methods of increasing friction 

Advantages and disadvantages of friction 

Some real life based situation where friction is applied.

How to make a monomer into polymer if it is an addition polymer example

This planet, _______ is yellowish in colour and has many rings and satellites.

A. Uranus

B. Jupiter

C. Neptune

D. Saturn

Pasteurized milk does not need to be boiled. Why?

Write the $pH$ value of the

1. Saliva (before meal)

2. Saliva (after meal)

3. Lemon juice

4. Colourless aerated drink

5. Carrot juice

6. Coffee

7. Tomato juice

8. Tap water