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?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

What have one eye but still cannot see?

What is the next number in this matchsticks series riddle?

What is full of holes but still holds water?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

I am a five-letter word and people eat me. If you remove the first letter I become an energy form. If you remove the first two letters, I am needed to live. Scramble the last three letters and I am a drink. What word am I?

What part of the chicken has the most feathers?

I am the largest in my family of fifty.
The youngest of our family lives separately from the rest of the family and so do I.
I am regarded as harsh and tough.
I am so large, you cut me in two equal halves,
each half would still be larger than the second largest member of the family.
Who am I?

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.