Meaning of ‘opposite’

You should mention the source. From this and some of your other questions, I'm guessing this is probably from Bill Mascull's Business Vocabulary In Use (Cambridge University Press). In the paper (printed) editions, these books are laid out so that exercises use two opposite pages. The even numbered pages (on the left) show example phrases, pictures, etc. The odd numbered pages (on the right) have questions for you to answer, which refer back to the material 'opposite'. These books are available online or in PDF form where the pages may not be shown in left- and right-hand pairs. On the question pages, 'opposite' means 'on the other page, to the left, that you can see'. Look on the previously numbered page, e.g. if the question is on page 48, look at the sentences on page 47

In printed material such as books or in electronic documents (such as pdf) formatted to simulate printed books, the content is laid out in two mutually facing pages.

As they read one page, the readers’s attention may be directed to material on the facing page by mentioning that it is “opposite”. An alternative way is to refer to “facing”.

Similar instructions are:

“Below”, for following material (usually but not always) on the same page;

“Above”, for preceding material (usually but not always) on the same page;

“Over” or “overleaf” for material on the other side of the paper page (or its notional electronic equivalent)