牙根发育完成后形成的牙本质是（）。

A.前期牙本质

B.继发牙本质

C.球间牙本质

D.修复性牙本质

E.管周牙本质

根据语境,填写适当的词语或句子补全对话.

A: What are you going to do next weekend?

B: I have no 1.       .What about you?

A: I don't know. Do you want to do something with me?

B: Sure. What do you want to do?

A: How about 2.         on Saturday?

B: OK. 3.         are we going to meet?

A: Let's meet at my house. My father has a boat. He can take us fishing on the lake.

B: What time shall we leave?

A: Let's leave at 5:00 in the morning.  Fishing is good at that time.

B: So early? Can we 4.         it a little later?

A: 5.       ,What about 5:30?

B: Great. We are sure to enjoy ourselves. See you at 5:30 on Saturday morning.

A: OK, Bye!