A system which can exchane energy with the surroundings but not matter is called.......system.

Explanation

To solve the question, we need to identify the type of thermodynamic system that allows for energy exchange but not matter exchange with its surroundings.

### Step-by-Step Solution:

1. **Understanding Thermodynamic Systems**:
- There are three main types of thermodynamic systems: open systems, closed systems, and isolated systems.

2. **Defining Each System**:
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