PHP Taskbook Level 9.3

Given an array of words, get a random word from this array that starts with a given letter.

Let's say we have a date 22.02.2017. This date has 4 twos. Find all dates with 4 twos in the current century.

A file with some arbitrary layout is given, inside of which there are links of the following type:

<div>
	text text text
	http://code.mu/ru/
	text text text
	https://code.mu/ru/
</div>

Read this file and send its text to the browser so that the links turn into a tags:

<div>
	text text text
	<a href="http://code.mu/ru/">code.mu/ru/</a>
	text text text
	<a href="https://code.mu/ru/">code.mu/ru</a>
</div>