Câu 11):  This building is ____ than that one.    A.  beautifuler          B.  beautiful                C.  more beautiful       D.  beautiful

Options B. beautiful and D. beautiful are not comparative forms, so they are incorrect.

Option A. beautifuler is not a correct comparative form in English.

The incorrect options are A. beautifuler, B. beautiful, and D. beautiful.

For example: This building is more beautiful than that one.

In comparative sentences, we use 'more' + adjective for two-syllable adjectives.