Answer:
Present tense sentence:
With a trembling hand, she reaches into the mailbox for the letter from her dream college.
Step-by-step explanation:
reaches is in the present tense.
All the other sentences are of different tenses
A faded postcard from Sweden and a tin of stale butter cookies were all that remained of those happy days with Sven (past tense)
The post box was full, but Molly shoved her tax return in with all the others(past tense)
I will drop these invitations in the mail on my way to work (future tense)