016.
One kind of vacation that many Americans enjoy is camping. Each summer, millions of Americans drive to the countryside where they find places to camp. The national parks, many of which are in the mountains, are favorite camping places. Campers enjoy the fresh air, the lakes and the forests which they find in these parks. Campers like, swim and fish. They can also find many kinds of animals and plants in the parks. Mostly, campers relax. They enjoy a change from their busy lives in the city. Some campers have trailers which they drive or pull behind their cars to their camp sites. Trailers are like houses on wheels. They have many conveniences which people have in their homes, such as electricity and hot water. But most campers don't have trailers. They camp in tents which they set up in their camp sites. Campers in tents don't have the conveniences that campers in trailers have. Tent campers enjoy a very simple life.

答案解析：
(1) 正确答案为C。根据 Campers enjoy the fresh air, the lakes and the forests.露营者享受新鲜的空气、湖泊和森林。以及They can also find many kinds of animals and plants in the parks.他们在公园里还会看到许多种动植物。可知，在国家公园里可以既可以看到动物也可以看到湖泊，因此C项正确。
(2) 正确答案为C。根据Each summer, millions of Americans drive to the countryside where they find places to camp.每年夏天，数百万美国人开车到乡村，寻找露营的地方。可知，他们是开车去露营地的，因此C项正确。
(3) 正确答案为A。根据campers relax.露营者在这里放松。以及campers enjoy a very simple life.露营者享受简单的生活。可知，人们喜欢露营的原因是他们可以放松并享受简单安静的生活，因此A项正确。
(4) 正确答案为B。根据They have many conveniences which people have in their homes, such as electricity and hot water.他们可以享受到在家中拥有的便利，比如电力和热水。可知，拖车露营者可以享受的便利是电力和热水，因此B项正确。