there are many pronlems that/which are too dangerous这里用that还是用which?

There are many animals______farm 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 There are many trees on____