英语语法问题1,during the summer holiday,several thousand people a

英语语法问题
1,during the summer holiday,several thousand people a day visit the park ,which is known for its waterfalls and rock formations 为什么不能改成during the summer holiday,knowning for its waterfalls and rock formations ,several thousand people a day visit the park
2tadpoles hatch and metamorphose into small replicas of adult frogs although remaining in their aquatic birthplace为什么要改成
2tadpoles hatch and metamorphose into small replicas of adult frogs while remaining in their aquatic birthplace