A. I don't know which one is the best for him.B. I'll take one.C. your son will enjoy playing with it.A: Good morning, sir. What can I do for you?B: Yes, please. I am leaving America soon. I want to buy an American toy for my son as his birthday present, but【D4】______A; How old is your son?B: Four years old.A: This is a "Panda Trucker". It is an electric toy. I think【D5】______B: Show me how it works, please.A: It's very simple. Put two batteries into this box, then turn on the switch, and the panda will drive the truck.B: What an interesting toy it is! 【D6】______I'm sure my son will be delighted. Here's the money.Thank you for your suggestion.A: You are welcome. Wish you a pleasant journey.