What is the function of the "Ctrl + Alt + Del" keys in

Statement: 

Each snickers are kit Kat.

Only a few snickers are dairy milk.

Few snickers are not munch.   

Statement:

Only a few Wood is Metal.

Only Metal is Glass.

No Metal is Marble

Conclusion:

I. No Wood is Glass.

Statements:No town is a city.

All cities are islands.

Conclusions:I. No island is a town.  

II. All islands are cities.

Statements-: 

Some Sons are daughter.

A few daughters is Mother

Many mothers is father

At most Sons are child.

Some fans are not switches. Some switches are not coolers. All invertors may be switches.

Statements:      

Some pigs are dogs.

Some dogs are cat.

Conclusions:

Statements: All circle are bangle.

                           Some bangle are square

Statement:

I) Some patient are maler

II) All male are doctor

III) No doctor is bad

IV) All bad are quacks