The largest shell is Tridacna gigas or the giant clam shell. There is also a pretty large shell in Australia called the Australlian Trumpet shell. And I am sure prehistoric shells were even larger then the ones of today.
The Catholic Church is the biggest charity in the worlds.
The Amazon is the worlds biggest rain forest
the worlds biggest yoyo is about the size of a hobo
It is a Irish Wolfhound and the male is at least 32"; and the female is at least 30"
There is no such thing as a biggest fraction, for the same reason that there is no biggest number. For example, if you have a large (finite) number, you can always add 1 to it to get an even larger number.
The Osprey Argon 110 (7100 cu.in in size large) and the Greggory Denali 105 (7000 cu.in. in size large) ar ethe two biggest available online.
The worlds biggest island is clearly Green Land its PNG
the worlds biggest volcano is Mauna Lao is in Hawaii
The worlds biggest selling drink is both Milk and water.
The worlds biggest tin sheep here
The worlds biggest pyrmiad is in egypt.It is among the seven wonders of world