A．It has the highest water cleanliness standard in Europe.
B．It has the best natural swimming pool in Europe.
C．It has the best purification specialist in Europe.
D．It has the cleanest river in Europe.

A．Whether the water is clean enough.
B．If it can be used in various weather conditions.
C．If it will lead to less visitors.
D．Whether the river traffic will be affected.

A．To separate the changing rooms from the pool.
B．To provide a path to the swimming area.
C．To make the pool shallow enough for children.
D．To protect people from waves caused by river traffic.