What month of the year has 28 days?

Count the number of times the letter "F" appears in the following paragraph:

FAY FRIED FIFTY POUNDS OF
SALTED FISH AND THREE POUNDS
OF DRY FENNEL FOR DINNER FOR
FORTY MEMBERS OF HER FATHER'S FAMILY.

What jumps when it walks and sits when it stands?

The more you take me, the more you leave me behind.
Who Am I?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

In an interview, a boy was asked an unusual question 'How two persons sitting with a table in between them can't see each other?' He was unable to reply. Can you?

I am white when I am dirty, and black when I am clean. What am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.