Task: Sentence Ordering
Input (English): Steps: (1) A virus enters a host body (2) The virus has receptors that lock onto a target cell (3) The virus uses the cell like a factory to make new copies of the virus (4) The new copies of the virus leave the cell (5) Infect other cells (6) The host gets sick as its cells are damaged.  
Where does the following step fit into the given list of steps: The virus enters the cell 
Output (English):  After step 2.