'Your faithfully' ' your sincerely' in the end of a letter are short for what? 'Your faithfully' ' your sincerely' in the end of a letter are short for what?

where can I get some audio listenning materials about years,money,numbers? where can I get some audio listenning materials about years,money,numbers? I bought a book ,but it read numbers separately,Do you know any links,sites?Thanks so much!

do i have wrong ideas about the 'of'? I worte two sentences today,which are not as correct as the context. 'peple's attitude toward consumption and the increase OF (in) disposable income are the main reasons behind the excessive consumption of disposable items. ' ...which can lead to a change OF(to) their lifestyles. Is there some rules or logic hehind the usage of 'of'? or it is just a used way to say？ Thank you!

when I need to do the phonetic combination? I heard these two phrases in a context: 'disposable income' the 'l' and 'i' are read together. 'disposable items' the 'l' and 'i' are read separately why ?Is there some rules &logic behind it?

the annoying 'the' Why use a 'the' before 2 and 3,but not before 1? Technological innovations and mass production have reduced the cost of ( 1 uncountable noun ) production and improved the( 2 uncountable noun ) productivity of the ( 3 uncountable noun )workforce.

the annoy 'the' Why use a 'the' before 2 and 3,but not before 1? Technological innovations and mass production have reduced the cost of ( 1 uncountable noun ) production and improved the( 2 uncountable noun ) productivity of the ( 3 uncountable noun )workforce.