Write the IUPAC names of the following compounds :
`{:(" "H_2 C-COOH),(" "|),(HO-C-COOH),(" "|),(" "H_2 C-COOH):}`

Explanation

To write the IUPAC names of the given compounds, we will follow a systematic approach to identify the main chain and the functional groups present. Let's break down the process step by step.

### Step 1: Identify the Compounds
We have three compounds to name:
1. H₂C-COOH (Acetic acid)
2. HO-C-COOH (Hydroxyacetic acid)
3. H₂C-COOH (Acetic acid again)

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