You use he to refer to a man, boy, or male animal.
You use it to refer to an object, animal, or other thing that has already been mentioned .
You use she to refer to a woman, girl, or female animal who has already been mentioned or whose identity is clear .
They'd is a spoken form of 'they had', especially when 'had' is an auxiliary verb .
They'll is the usual spoken form of 'they will'.
They're is the usual spoken form of 'they are'.
They've is the usual spoken form of 'they have', especially when 'have' is an auxiliary verb .
as…as they come:
the most characteristic example of a class or type
kick someone when they are down:
to hurt, upset or criticize someone when they are already in a weak position or at a disadvantage
such as it is/such as they are:
You use such as it is or such as they are to suggest that the thing you have just mentioned is not very good, important, or useful .
they broke the mould when they made someone:
said to mean that a particular person or thing is special or unique, and that there is nobody else or nothing else quite like them
let the chips fall where they may:
let the consequences be what they may
as good/stupid/quick etc as they come:
If you say that someone is, for example, as good as they come, or as stupid as they come, you are emphasizing that they are extremely good or extremely stupid.
count one's chickens before they are hatched:
to be overoptimistic in acting on expectations which are not yet fulfilled
give someone an inch and they'll take a mile:
said to mean that if you do a small favour for someone, they will become greedy and ask you to do bigger and bigger favours for them and make you regret doing the first favour
as good (or tough or strong, etc.) as they come:
among the best (or toughest, strongest, etc.)
someone will cross that bridge when they come to it:
said to mean that someone intends to deal with a problem when, or if, it happens, rather than worrying about the possibility of it happening
someone can do something until they are blue in the face:
said to mean that however long someone does something or however hard they try, they will still fail
don't count your chickens:
said to mean that you should not make plans for the future because you do not know for certain how a particular situation will develop