英文tense的問題

Hi,
1)
My pen is lost and was left at home. OR
My pen has been lost and left at home.<--OR
My pen is lost. I left it at home. OR
I've( I have) lost my pen. I think I left it at home. OR
My pen is lost. I must've left it at home. ( must've = must have)

Note: Don't forget to capitalize the first word in a sentence.
The part in green is my choice.
_______________________________________
2)
1) She wants to study hard and get good results( a good result) in ( that/the) exam.
2) She wants to study hard and to get good results(a good result) in ( that/the) exam.
Note: Actually both sentences are ok, but the first one is much better.
You may choose the first one then.
Also, I have never studied in Hong Kong. I have no clue
how many results a student may get in an exam.
If you guys get some or many results, write " to get good results " then.If not, change it to " to get a good result.....".


Suggestions for you:
1) Always capitalize the first word in a sentence.
2) When you come across countable nouns, you have to check if
you'd use an article. (" Exam" is a countable noun( not a phrase) in the sentences, so you have to use a certain word or article.)
Which exam are you talking about?
Is it the exam? or Is it that exam?

That's it.

Good luck with your studies.
Ciao

1. my pen is lost and left at home.
2. she wants to study hard and get good results in exam.
希望幫到你啦!!!