What kind of band never plays music?

Sally lives in a place where six months of the year is mild summer and the temperature drops significantly the other six months. She owns a lake where there is a small island. She wants to build a house on the island and needs to get materials there. She doesn’t have a boat, plane, or anything to transport them to the island. How does Sally solve this problem?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

If you say my name, I will no longer exist. What am I?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

Count the Triangle in the figure given below: