問問大家英文時式的問題

獨立來說tense冇錯，不過句子可以寫成:

Hi, Mary, I am Steven who have ordered the ten products { }.

我不知你這是真實寫去你的供應商還是只是練習寫作
假如是真實的話{ }位置最好附加on日期或with訂單編號等資料

I would rephrase it like the following:
Hi Mary, I am Steven. I have ordered ten each of the products you needed. (I would assume that there is something more after the term "products").

1. Mary後面要full stop (.)
2. 如果係對話(面對面/手機)，唔使用present perfect，所以唔使要have
3. the 字唔使要(如果ten products係解10件貨而唔係專有名詞)