So Hotels have developed A. as rapidly as restaurants.

• "As rapidly as" is the correct comparative structure for showing equality.

Can Tho bridge is the D. longest.

• "Longest" is the superlative form of "long."

Impalas cannot move as C. fast as cheetahs but they are more efficient runners.

• "Fast" is the correct adjective to use for comparison.

She is the C. most beautiful girl in our town.

• "Most beautiful" is the superlative form of "beautiful."

Jim is the B. cleverest in his class.

• "Cleverest" is the superlative form of "clever."

According to a recent study in the UK, about 70% of teen girls are D. keen on reading books.

• "Keen on" is the correct phrase.

Her grandfather D. died ten years ago.

• "Died" is the past tense of "die."

Children are also keen B. on martial arts because they can improve their skills.

• "Keen on" is the correct phrase.

My mother A. always goes to the market by bike.

• "Always goes" is the correct structure.

Of the two shirts, this one is B. the prettier.

• "The prettier" is the correct comparative form for two items.

The test is not D. Both A & B are correct.

• Both "as difficult as it was last month" and "so difficult as it was last month" are grammatically acceptable.

I D. will visit you as soon as I finish my work.

• "Will visit" is the correct future tense form.

The Nile River is B. the longest of all.

• "The longest" is the superlative form of "long."

Peter cannot earn B. as much money as his wife.

• "As much money as" is the correct comparison.

Of the five students, Mary D. is the most intelligent.

• "The most intelligent" is the superlative form.

Some teenagers are really A. into photography.

• "Into" is the correct preposition.

Steel is C. heavier.

• "Heavier" is the comparative form of "heavy."

Tim's grades are B. worse than John.

• "Worse" is the comparative form of "bad."

Students C. are doing an English test at the moment.

• "Are doing" is the correct present continuous tense.

Mai C. has lived in Ha Noi with her aunt since 2010.

• "Has lived" is the correct present perfect tense form.

The new member is A. more quick than we expected.

• Note: The correct form should be "quicker," but based on the options given, "more quick" fits best