He is incorrect because a catalyst is a substance that speeds up a chemical reaction so if there is no reaction to begin with a catalyst will not due anything.
<span>The correct answer is that he has injured one of the tendons or ligaments that help keep his knee in place, connecting it to the surrounding muscle and bone. As a result of this injury, his knee is no longer connected to the muscle and bone, thus it wobbled sideways when he started walking. He needs to go to a doctor immediately who can fix his knee so as to prevent further complications - he just needs his knee to be set in place again.</span>
1. It requires two parents.
<span>2. It takes time and energy.
</span><span>3. It can prevent favourable genes from being passed to offspring.
</span><span>4. It produces fewer offspring than asexual reproduction.
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You didn't give options so I couldn't properly answer your question.
However, hope this helps xox :)
