How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

It is a six-letter word.
The first four letters are me.
The second and last letters are the same.
The fourth second and last letter is payment.

Who is it?

I travel all around the world but always stay in the corner. What am I?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

What work can one never finish?