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) 正確答案為C。根據(jù) Campers enjoy the fresh air, the lakes and the forests.露營者享受新鮮的空氣、湖泊和森林。以及They can also find many kinds of animals and plants in the parks.他們在公園里還會看到許多種動植物。可知，在國家公園里可以既可以看到動物也可以看到湖泊，因此C項正確。
(2) 正確答案為C。根據(jù)Each summer, millions of Americans drive to the countryside where they find places to camp.每年夏天，數(shù)百萬美國人開車到鄉(xiāng)村，尋找露營的地方。可知，他們是開車去露營地的，因此C項正確。
(3) 正確答案為A。根據(jù)campers relax.露營者在這里放松。以及campers enjoy a very simple life.露營者享受簡單的生活。可知，人們喜歡露營的原因是他們可以放松并享受簡單安靜的生活，因此A項正確。
(4) 正確答案為B。根據(jù)They have many conveniences which people have in their homes, such as electricity and hot water.他們可以享受到在家中擁有的便利，比如電力和熱水。可知，拖車露營者可以享受的便利是電力和熱水，因此B項正確。