Crying for one hour, the new parents tried to pacify the baby. What modifier are you talking about?
Students in/of the biology class were studying slides of plant tissues. Correct
I found a ten dollar bill (whilst) walking across campus. 10$ bills can't walk, insert whilst to remove the ambiguity.
Hearing a loud noise, we all looked out the window. Correct 'Hearing a loud noise' is an absolute phrase, not really part of the sentence.
He is blowing out the candles of his birthday cake in the picture. Faulty Modifier ¿Donde esta la tarta? y ¿donde esta el? The sentence is ambiguous.
'In the picture he is blowing out the candles of his birthday cake .
Student or Learner