Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the   correct word or phrase that best fits each of the numbered blanks from 28 to 37. Fill in the appropriate word in question 35

In most of the earliest books for children, illustrations were an afterthought. But in the Caldecott "toy books" which first (28)............ in 1878, they were almost (29)............ important as the lines of text,  and occupied far more space in the book. One can almost read the story from the dramatic action in the pictures. (30)............ then, thousands of successful picture books have been published in the United States and around the world. In the best, the words and illustrations seem to complement each other perfectly. Often a single person is responsible (31)............ both writing and illustrating the book. One of (32)............, and certainly one of the most successful, illustrator-authors was Dr. Seuss, (33)............ real name was Theodor Geisel. His first children's book, And to Think That I Saw It on Mulberry Street, hit the market in 1937, and the world of children's literature was changed forever. Seuss's playful drawings were a perfect complement to his engaging stories and (34)............ characters. In 1957, Seuss's The Cat in the Hat (35)............ the first book in Random House's best-selling series, Beginner Books, written by Seuss and several (36)............ authors. These combine outrageous illustrations of people, creatures, and plants, and playful stories written (37)............ very simple language.

A. became

B. had become

C. would become

D. has become