input: Please answer the following: What is the missing first step of the following process:  -  Water seeps into the remains - Minerals dissolved in the water form crystals - Crystalized minerals cause the remains to harden - The minerals form a fossil.
++++++++++
output: An organism dies


input: Please answer the following: What is the missing first step of the following process:  -  The receptors will lock onto a target cell using these chemical receptors on the surface, which docks onto the cell surface - The receptors  then go into the cell - The receptors use it like a factory - The receptors take it over and make it produce thousands or in some cases millions of copies of new viruses - The copies come streaming out of the cell - The copies infect other cells to make more viruses, or they escape from the body and infect a new victim -
++++++++++
output: The flu virus has receptors, which are like viral Velcro, on the surface of the virus particle


input: Please answer the following: What is the missing first step of the following process:  -  Rain picks up carbon dioxide as it falls to earth - The rain falls on the soil over the limestone - The carbon dioxide in the rain washes through the soil - The carbon dioxide turns into acid - The acid in the rain gets to the limestone below the soil - The acid dissolves the limestone - Acid continues to erode the limestone with more rain over time - The eroded limestone sometimes forms caves.
++++++++++
output: Limestone is located under the soil


input: Please answer the following: What is the missing first step of the following process:  -  Air reaches the lungs - The lungs absorb the oxygen from the air - The oxygen is transported by hemoglobin - Red blood cells are made of hemoglobin - Blood has a lot of red blood cells - The heart moves the blood throughout the body - Blood can bring the oxygen to different cells in the body.
++++++++++
output: