dear sir , please explain 1. it is a short time marriage of necessity. 2.that is what the facsimile machine is all about[ what does all about mean? ] 3.hi voice took on an extra decibel of joy. 4. virtual cradle-to-grave security.
1) When two unlikely business rivals work together to develop a product or service it is often called a "marriage of necessity". Example: Microsoft and Apple are working together to develop a new computer. It is a marriage of necessity for both companies.
2) "all about" means inclusively about. In reality you can drop the "all" in most cases and not change the meaning.
3) "extra decibel of joy" this expressing in an music based idiom. Often when people are happy they sing so an "extra decibel of joy" just means they are very happy.
4) "cradle-to-grave" an idiom which means from beginning to end. You will see this used a lot in business record keeping.
I hope this was helpful ;-)