Rewrite the following sentence to eliminate cliches, jargon, and redundant language.
1. it would appear that a large number of houses were damaged subsequent to the flood.
2. i think that in my opinion we have a chance to really take the bull by the horns and make hay while the sun shines.
3. if we fail to act, the true fact is that the riverbanks will continue to keep eroding unless we do something.

1. It would appear that a large number of houses were damaged after the flood.

2. In my opinion, we have to deal with the problem right now and get the most of it while we have a chance.

3. If we fail to act, the fact is that the riverbanks will continue to keep eroding unless we do something.

Explanation:

To rewrite these sentences we need to know what are the definitions of cliche, jargon, and redundant language.

Cliche is an expression that has been so overused that it has become boring and unoriginal.

Jargon is a literary term of special words and phrases that are used by a particular group of people, especially in their work.

Redundant language is the repetition of the same idea or item of information within a phrase, clause, or sentence (tautology).

1. it would appear that a large number of houses were damaged subsequent to the flood.

Jargon - subsequent to. Instead, we can use the word after.

It's better to write:

It would appear that a large number of houses were damaged after the flood.

2. i think that in my opinion we have a chance to really take the bull by the horns and make hay while the sun shines.

I think that in my opinion - redundant language.

Cliche - to really take the bull by the horns, and make hay while the sun shines.

Also, the word really is redundant here.

It's better to write:

In my opinion, we have to deal with the problem now and get the most of it while we have a chance.

3. if we fail to act, the true fact is that the riverbanks will continue to keep eroding unless we do something.

Redundant language -  the true fact. True fact creates a tautology.

It's better to write:

If we fail to act, the fact is that the riverbanks will continue to keep eroding unless we do something.

active voice: my father cut the tree.

passive voice: the tree was cut by my father.

active voice: people buy newspapers every day.

passive voice: newspapers are bought (by people) every day.

active voice: people have been using movies as political propaganda since world war ii.

passive voice: movies have been used as political propaganda since world war ii.

active voice: donna gave me my birthday present.

passive voice: i was given my birthday present (by donna). / my birthday present was given to me (by donna).

active voice: mom will leave the keys on the counter.

passive voice: the keys will be left (by mom) on the counter.

the words in parentheses are the agent of the passive voice and can be omitted when obvious, generic, or simply unnecessary.

in our power to make a world happy - to teach mankind the art of being so - to a character hitherto unknown - and to have, as it were, a new creation intrusted to our hands, are honors that command reflection, and can neither be too highly estimated,