1) A cloze test involves removing words from a text at regular intervals and having test takers fill in the blanks, while a C-test removes the second half of every second word.
2) Both aim to test reading comprehension, but C-tests allow for more items from shorter texts and can be scored more objectively.
3) Advantages of C-tests include allowing a representative sample of language elements, being less time-consuming for students than cloze tests, and having objective scoring. Disadvantages include lower face validity and potential focus on vocabulary over comprehension.