Pronunciation is important
Some learners of English think that pronunciation is not very important. That is (26 ABSOLUTE) wrong.
Even if you have an acceptable grasp of the English language, with good grammar and an (27 EXTEND) vocabulary, native English speakers may find you very difficult to understand you if you don't work on your pronunciation.
Correct, clear pronunciation is (28 ESSENCE) if you really want to improve your level of English.
Pay particular attention to any sounds that you are (29 FAMILIAR) with or that do not exist in your native tongue.
For example, (30 RUSSIA) have difficulty pronouncing the “th” sound, as it does not exist in their native language.
Remember that the pronunciation of certain English words varies depending on the part of the world it's spoken in. For example, American English differs (31 GREAT) from British English.