从下列方框中选择恰当的句子填空，使对话完整、通顺，其中有一项多余。

A: I'm going to the school party this Friday.

B: 1______. Let's bring some snacks.

A. 2______.

B: Really? Why not?

A: 3______ the teacher will be angry.

B: Well, can we wear jeans to the party?

A:  4______. If we wear jeans.the teacher will not let us in.

B: Should we bring our ID cards?

A: Sure. If we don't. 5______.

在跨度较大的屋盖结构中，采用桁架比采用梁的优点是（）

A.形式美观

B.施工方便

C.受力合理并且自重轻

D.有利于屋面排水