Why is it difficult to climb up a greasy pole ?

Why is it difficult to walk on sand?

Why is it difficult to aim and hit targets under water, such as fish?

Why is it difficult to walk on solid ice?

Why is it so difficult for biologists to agree on a classification of protists?

Why is it difficult to prepare pure amines by ammonolysis of alkyl halides?

Why is it difficult to hold a school bag having strap made of thin and strong string?

Explain, why is it difficult for a fireman to hold a hose, which ejects large amount of water at a high velocity?

Why is difficult to read the image of the text of a page formed due to reflection by a plane mirror?

Why is it difficult to differentiate between red and green colour objects in dark or in night ?

Why it is more difficult to rotate a stone by tieing it to a longer string than shorter string ?