The `C_(4)` plants are twice as efficient as `C_(3)` plants in terms of fixing `CO_(2)` but lose only ...... as much water `C_(3)` plants for the same amount of `CO_(2)` fixed.

Explanation

To solve the question regarding the efficiency of C4 plants compared to C3 plants in terms of CO2 fixation and water loss, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding C3 and C4 Plants**:
- C3 plants use the Calvin cycle for photosynthesis, which directly fixes CO2 into a three-carbon compound.
- C4 plants have a modified pathway that allows them to fix CO2 more efficiently, especially in conditions of high light intensity and temperature.

...