In this task, you will be given a sentence or two along with a change aspect. You should change the given text in the given aspect. Aspects are explained below:
 Tense: Change the tense of the verbs in the text. If they're in past tense, change them to present, and if they're in present tense, change them to past tense.
Number: Change the number of the nouns in the given text. Make plurals into singles and single into plurals. Remember to change the corresponding pronouns accordingly.
Voice: If the verbs are in active voice, change them to be passive, otherwise, change them to be in active voice.
Adverb: add one or multiple adverbs to the text.
Gender: If the text contains female names and pronouns, substitute them with male names and pronouns. Do the same for sentences with mala names and pronouns.

Let me give you an example: sentence: Jim signaled the barman and gestured toward his empty glass . aspect: Number
The answer to this example can be: Jim and Bill signaled the barmen and gestured toward  their empty glasses .
Here is why: You have to add people names and change the pronouns if you want to change the number aspect of the sentence.

OK. solve this:
sentence: Three species of fish that have recently been found living in the Indian Ocean are being studied by scientists . They began two years ago . aspect: Voice
Answer:
The scientists are studying three species of fish that have recently been found living in the Indian Ocean .  They began two years ago .