You're wrong .( ) my starting,I have the same opinion with you.but.括号里填什么啊,

You're wrong .( ) my starting,I have the same opinion with you.but.括号里填什么啊,
You're wrong .( ) my starting,I have the same opinion with you.but.括号里填什么啊,

You're wrong .( ) my starting,I have the same opinion with you.but.括号里填什么啊,
At.
题句其实应该是
You're wrong.At my starting,I had the same opinion with you,but...
根据楼主的题句,这里只能用at,但说实话我并不同意这样的说法,这句话的意思是“你错了.我一开始跟你想得一样,但是...",通常会说成
You're wrong.At the beginning,I had the same opinion with you,but...

应该是on.
on加现在分词短语放句首，意思是 一···就···
连起来就是“一开始，我跟你想的一样”

at 你错了。 开始的时候我也跟你想的一样，但是

AT起初时