Insert the missing sentences into the text: Thanks to modern technology, scientists and researchers can generally find an explanation for things that might initially seem mysterious. 1(). Here, just outside the town of Gryfino, Poland, a 20th-century mystery has still not been explained. Known locally as Krzywy Las, the Crooked Forest, planted in around 1930, contains about 400 neatly arranged pine trees. There is nothing unusual about forests such as this in this area. 2 (). Surrounded by a forest of trees that stand up straight, the trees in the Crooked Forest have an unusual 'C-shape' at the base of their trunks. What's more, the majority of these shapes face north. What could possibly have caused the trees to grow in this mysterious way? There are plenty of theories about how and why the trees have this curious appearance. 3 (). One theory is that this particular area of the forest experiences a unique type of gravity which has caused the trees to grow in this odd way. However, scientists have dismissed this explanation because gravity pulls things downwards - it doesn't make things curve. Similarly, scientists don't believe the idea that it happened naturally because the trees are too uniformly curved for this to be the reason. One of the more likely explanations is environmental. 4 (). Perhaps, when the trees were very young, the snow weighed down the saplings causing them to bend and then grow upwards towards the light. However, this doesn't explain why this only happened to the trees in the Crooked Forest, and why those in the surrounding areas grew straight. Another possible reason might be that people did this on purpose. Maybe farmers curved the trees in order to have specially-shaped wood for furniture or shipbuilding. 5 (). Native Americans, for example, did this so that when they passed an oddly-shaped tree on a journey, they knew exactly where they were and which direction they needed to go in. But if the Polish farmers planted the trees for a particular reason, the question is: why didn't they cut them down and use them? 6 (). The nearby town of Gryfino, along with most of its inhabitants, was virtually destroyed during World War II and the town wasn't rebuilt until the early 1970s. The people who used to live there, including the farmers who worked in the forest, never returned. Therefore, it seems that even if the farmers knew the reason for the Crooked Forest, the secret is lost forever and the mystery remains. Choose from the sentences A - G the one which fits each gap (1-6). There is one extra sentence which you do not need to use. A Polish winters can be severe and there is frequent heavy snowfall. B But what is strange is how these trees have grown. C The most probable answer is that the forest was simply abandoned. D None of the locals go into the mysterious forest. E There are other reasons too, why people bend trees into shapes. F Some explanations are highly unlikely, but others are more sensible. G However, in one forest in a small corner of western Poland, this hasn't been the case.