Russian learners of English often replace the English [b, p] by the Russian [б, п].
This is a phonetic mistake.
The lips could be pressed together more energetically to make [p] string (напряженный) and aspirated (с придыханием).
Word contrast practice is very useful here to show the difference in meaning:

      rip (кляча) – rib (ребро),
      cap (кепка) – cab (такси),
      rope (канат) – robe (халат),
      tap (пробка) – tab (вешалка) 

Tongue Twisters

Pip and Pete shipped the sheep ships cheaply.

Those bins are for Bill Beal’s beans. ("ea" – [i:])

Pick cherries at there peak or Pete will see the pits.

Beach bins are filled with field filler.

А теперь прочтите все еще раз самостоятельно:

Pip and Pete shipped the sheep ships cheaply.

Those bins are for Bill Beal’s beans. ("ea" – [i:])

Pick cherries at there peak or Pete will see the pits.

Beach bins are filled with field filler.