A Jig saw puzzle pieces are in different colors which have different shapes. 

You can put it anywhere you like but there is only one right place for it to be fit in it.

1) If they use the same cutting board/counter to cut raw chicken, and other foods with out sanitizing in between. 

2) If they have a cold, flu, or pink eye and are handling food, coughing without covering their mouth, then washing their hands.

3) If they don't properly wash their vegetables.

4) Not storing foods at proper temperatures.

And so many other reasons for Food handlers can contaminate food.

An orthodontist is the type of doctor that specializes in teeth and jaw alignment. When the teeth don't align properly, it can cause uneven wear in the teeth.

The jaw is a hinge joint. Strong muscles in the face open and close the jaw. Teeth are implanted in the jaw and serve to rip, tear and crush food in preparation for swallowing it.

The relationship between a cathode and an anode involves the transfer of electric charge between them. The cathode is the negative terminal on the battery, which has zero electric potential. The anode is the positive terminal on the battery and has the battery's maximum electric potential. Current flows from the battery's anode (positive terminal) to the cathode (negative terminal). In electron flow, electrons leave the negative side of the battery and move towards the positive side of the battery.

Hence, The relationship between a cathode and an anode involves Electrons.

Given that,

Members in football team = n(f) = 10

Members in science club = n(s) = 14

Members in both football team and science club = n(f ^ s) = 5

Then, Members in only football team = n(F) = 10 - 5 = 5

Members in only science team = n(S) = 14 - 5 = 9

Hence, members in only football or science team = n(FUS) = n(F) + n(S) - n(f^s) 

= 9 + 5 - 5

= 9.

Hence, many students belong to only science club team or football team = 9.

A Match stick. 

You tear a match out of a matchbook and scratch the head to light it, then the red tip turns black from the flame.

The difference between 4632 and 20000 is given by subtracting smaler number from the bigger number.

Here the bigger number is 20000

Smaller number is 4632

Now, subtracting 4632 from 20000

20000 - 4632 = 15368 and the resut is an even number.

Hence, The difference between 4632 and 20000 is 15368 and is an even number.