The commonwealth games were not held during 1945 and 1946 because of World War 2. Ever since then, they've been held regularly every 4 years.
Formal language is also called "proper language" because it is the type of language you would use when first meeting someone or giving a speech at a high class place so the correct answer is:
<span>B) Have I convinced you that the study of grammar is important and well worth your effort? </span>
