37. The book's written by my brother. Don't you find it __________ .
[ A ] interested [ B ] interesting [ C ] interest
38. Can you help me? I can' t find my key __________ the door anywhere.
[ A ]with [ B ]in [ C ]to
39. Sally must be very sad. She was __________ crying in her bedroom.
[ A ] to see [ B ] seen [ C ] seeing
40. Mary is a famous writer though she is still __________ her twenties.
[ A ] about [ B ] on [ C ] in