改错I am very glad,I can swim as good as Anna now

I am very glad (that) I can swim as （well） as Anna now.或 I am very glad,(because) I can swim as good as Anna now.（英语中,两个分句应该用连词连接形成一个并列句或者复杂句,不能直接用逗号连接；动词swim应该用well修饰,而不是形容词good.）
You must do your homework (as) our teacher told you,or you will make a few mistakes.(like 只能做动词,表示“喜欢”,或者做介词,表示“像...”后接名词或动名词；而as可做连词,表示“如...”后接句子)
Don't be afraid (of) the tiger.It's tied to the big tree.（afraid的固定用法,表示“害怕”应该用介词of）

修饰swim动词 怎么能用 good？as our thacher told you ， as正如，就像的意思

1 good -> well（ 修饰动词用副词）
2 like - as （按照……）
3 with -> of （固定词组be afraid of ‘ 害怕’)

be afraid of; I am very glad that I can swim as well as; as our thatcher told you to