Are the following statements true?

1. The free surface of a liquid is its surface in contact with the air.
TRUE FALSE

2. The free surface of a liquid is always flat and horizontal.
TRUE FALSE

3. The plumb line materializes a horizontal line.
TRUE FALSE

4. A level is used to check if a surface is vertical.
TRUE FALSE

5. In a wide and tilted container, the free surface of a liquid at rest is not horizontal.
TRUE FALSE

6. When the container is tilted, the free surface of a liquid at rest cannot be vertical.
TRUE FALSE

7. A meniscus is the curved free surface of a liquid present in a narrow container.
TRUE FALSE

RESULT: