Complete the following by suppling intermediates
`MeCH_(2) C=- CH overset(Na//liq. NH_(3))(to) [A] overset(EtBr)(to)[B]`

Explanation

To solve the problem, we need to identify the intermediates A and B in the reaction sequence given. Let's break down the steps involved:

### Step 1: Understanding the Starting Material
The starting material is `MeCH2C≡CH`, which can be rewritten as:
- `Me` = Methyl group (CH3)
- `CH2` = Methylene group
- `C≡CH` = Terminal alkyne (ethyne)

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