很简单的一些英语句子（小学初中级别?）,帮我挑语法错误,

很简单的一些英语句子（小学初中级别?）,帮我挑语法错误,
不要看很长,其实很简单的.帮我整体看一下,挑出语法错误并改正就行了.如果那一整句都有问题,可以直接按中文意思重新翻译一句出来.
Today we're going to tell you a joke.
There are a lot of animals in the forests (森林要不要加s?前面是in还是on啊?)They held a party last week.The hare（野兔） and the bear are good friends.They took part in（还是join?attent?） the party together.
Hi,bear!Now I have a bag.(Now可以这样用么?) There are something delicious in it.
Oh.Can you tell me what are these?(用these好还是they好?)
If you can guess,I'll give all the cakes in the bag to you.(有没有语法错误?)
Let me think.Hmm...Are these（或者用there?） apples?
No!By the way,why do you think apples are delicious?
An apple a day,keeps the doctor away.(这句话是这么说的么?)
Do you know how many cakes there are?If you can guess,I’ll give you all the five cakes.(这句话好像是中式英文.中文意思是：如果你能猜中,我将把这5个蛋糕都给你.帮我翻译一下吧.)
Are there ten cakes?
Oh.You have guessed wrong again.But it is really too difficult to guess,right?
Yes,and can we begin eating now?
帮帮忙啊英语帝们..小弟感激不尽啊.