This tunnel has no intersections, which means you can draw line from the entrance to the exit without lifting your stylus.
UK Version
This tunnel has no intersections, which means it forms a continuous line from the entrance to the exit.
US Version
There are no other ways out of the tunnel besides the entrance and exit.
As you can see, the piece in the bottom-right corner has to be a bend, and it's clear which way it has to turn. The top-left corner needs to be a bent piece to connect it to the fixed piece on its right.
These are the types of hints you should use to figure out the puzzle bit by bit.
UK Version
There are no other ways out of the tunnel apart from the entrance and exit. As you can see, the segment in the bottom-right corner has to be curved and it's clear which way it has to turn. The segment in the top-left corner also has to be curved so it can connect to the fixed piece on its right.
These are the types of little hints you should use to work this puzzle out, bit by bit.
US Version
Thanks to Hint Two, you now know what the first two pieces of the tunnel are. Moving on from there, you should be able to determine the third, fourth, and fifth pieces from the entrance.
Try and integrate the nearby fixed piece into the sequence and it's clear what the next two pieces are.
UK Version
You can use the information from Hint 2 to determine the third, fourth and fifth segments from the entrance.
Try to integrate the nearby fixed segments into the sequence and it's clear what the next two are.
US Version
The piece beneath the exit is straight, and the piece below that connects to the fixed piece to its left.
You can figure out the rest.
UK Version
The segment beneath the exit is straight, and the piece below that connects to the fixed segment on its left.
