there are many organizations to help the deaf and blind ,请问里面的to 是什么成分,或者启一个什么作用,及为什么要加这样一个to

There are many animals______farm organ There are many sweets. There are many fruits, too how many legs are there? There are many reasons____travelling abroad. There are many sweets.翻译 there are many differences between how many stop are there there are many _____________(fish ) How many pears are there? How many stars are there? How many birdges are there? HOW MANY BOOKS ARE THERE there are many things（） How many people are there? There are many horses是什么意思 There are many fritus.(改错) There are many trees planted