1.Let nature take its course- to allow someone to live or die naturally.
2.Like a sitting duck- totally unaware
3.Lion’s share- a major share
4.Left to your own devices- If someone is left to their own devices, they are not controlled and can do whatever they want
5.Make castles in the air- plans or hopes that have very little chances of happening.
6.Make a bee line for- to go directly towards something.
7.Make ones bed and lie on it- to be responsible for what you have done and accept the results
8.Meet ones waterloo- meet ones final end
9.Monkey around- to waste time here and there
10.My hands are full- I am busy