Coral reefs are large structures in the sea. A coral reef is the remains of tiny organisms. The reef is hard. Animals use it for shelter. Some animals find food there. One type of crab helps the coral. The crab lives in the coral. It
takes tiny pieces of dirt and sediment away. By clearing the dirt, the crabs help the coral.

A: carry
B: feed
C: make
D: clean

Select all the correct answers. lactobacillus is a bacteria that live inside humans. these bacteria live on the nutrients from our bodies. they to keep our gut clean and healthy. s. typhi is a bacteria that enter our bodies through contaminated food. this bacteria causes infections in the body. based on this information, which two statements about the association between these bacteria and humans are true? a. lactobacillus shares a parasitic relationship with humans. b. s .typhi shares a parasitic relationship with humans. c. both lactobacillus and s. typhi share a parasitic relationship with humans. d. both lactobacillus and s. typhi share a mutualistic relationship with humans. e. lactobacillus shares a mutualistic relationship with humans, and s. typhi shares a parasitic relationship multiply chrse

When lactate builds up in a runners muscles it causes a burning sensation what causes this to occur

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.