Solution:

A pen cannot write even a single world. It's the person holding the pen who can write the words.

Solution:

The cheerleaders.

Solution:

A HouseFly.

Solution:

when you are a mouse.

Solution:

She was not able to find 11 on phone.

Solution:

she cant find 11 on phone.

Solution:

Simple, the slow ones are in prison :-)

Solution:

It is because there is not a single (unmarried) person it.

Solution:

Both of them were able to cross the river because they were standing on the opposite sides of the river.

Solution:

The question tells us that a taxi driver was going the wrong way. It is however not mentioned that he was driving the cab. As per the question, it is evident that he was on foot and that is why the police officer did not fine him.