What is the best time to visit the park? ______ is the best time. [originaltext]

Welcome to our park. My name is Linda. I’m very glad to be your guide today.(16) You have made a right choice to be here in spring, the best time of the year, because summer is a bit hot, and winter is too cold.(17)Our park is famous for its 20-kilometer long valley. It’s the home of thousands of plants and animals. For today’s tour, we have a 50-minute valley walk in the morning. You will see beautiful flowers and strange rocks.(18)Animal lovers can also have a close view of different wildlife.(19) In the afternoon, you’ll have a chance to experience some interesting activities, such as boating and fishing. If you like,(20) you may have a picnic by the lake, the best-loved activity in our park. Now, let’s get on the bus and go to the entrance to the valley.