Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

How many words can a pen with half refill write?

Which country gets ill every time?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?

John is pretty weird. He likes toffees but hates chocolates. He loves books but never reads. He likes to build his troops in an online game but does not proceed with the war. He likes to go swimming but is afraid of water.

Seeking this behaviour, can you tell whether he likes balloons and parties?

Who always enjoys poor health?

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

Replace the question mark with the correct number below.

By what process could you make a 'Tea-Table' into food?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?