Hieroglyphs are written in the ancient language. Hope this helps
A Clarity because clarity means the same as "how clearly". Or the measurement of "how clear something is", like the clarity of water. If you practiced new Vocab words with good clarity or with clarity, it means you understand them and can spell them well.
An allusion is an expression designed to call something to mind without mentioning it explicitly; an indirect or passing reference.
'That' is A, a demonstrative pronoun. Because you are referring to that person, you are basically pointing at your cousin, therefore it must be a demonstrative pronoun.
