用方框内所给词语的适当形式填空，使文章通顺、完整。（每词限用一次）

how   look  many    able  as  crowd    find   problem   for   comfortable

Do you think people will work and live in the sea in the future? You may ask. “_________will people go to work then?” By submarine(潜水艇)! Some scientists believe that some day submarines will be as ________ as today’s cars.
A French driver says, “One day, man will travel in the sea _________they do in the street!”
If humans want to live in the sea, they have to solve (解决) a lot of ___ first. For example, what will happen to our body if we stay in the water _________ a long time?
Scientists are _________ for the answers. Maybe in 50 years man will be _________ to live in the sea. They will be away from the _________ cities. Man will _________that it’s fun and interesting to live in the sea, and that life in the sea is more _________. Don’t you think so?