Which sentence uses correct punctuation? many countries are making progress to solve environmental problems; however, there is more to be done. many countries are making progress to solve environmental problems, however, there is more to be done. many countries are making progress to solve environmental problems, however; there is more to be done. many countries are making progress to solve environmental problems, however there is more to be done?

Many countries are making progress to solve environmental problems, however, there is more to be done. 

The details about the statues, i believe, are that they're carved from blocks of igneous stone, many of them are partially buried under the ground which to preserve and protect them from the harsh environment on easter island, and many of the facial features have washed away. also, the most well-preserved one is at the british museum in london.these are just guesses from what i can see and what i think i read correctly. i'm sorry i couldn't be more .