Waves that crash against the beach contribute to the blank of the shoreline A. deposition
B. Evaporation
C. Build up
D. erosion

this a full in the blank. so get rid of the word blank and put in the best answer choice.

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.