What work can one never finish?

_ _ _ IE _ _
_ _ _ IE _
_ _ IE _ _
_ _ IE _
_ _ _ _ IE

Like you see, some letters have gone missing from these words that contain the IE pair at some or the other place. The letters that will be used to fill the blanks are given below. Use them and form meaningful words. Can you do that?

A, C, D, F, H, K, L, M, N, N, O, R, R, S, S, S, T, T, Y and Y.

What brings you down but never up?

How can you make number one disappear by adding something to it?

By using 'because' continuously three times, can you make an English statement ?

Which alphabet is a part of our body?

Can you divide the below-given shape into four equal and identical pieces?

What word is identified by the below rebus?

Your Your Your Your Your
Your Your Your Your Your

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Can anyone tell me a word in the English dictionary which has a silent 'z'?