看图，完成对话。

Betty: Hi. Jim !   1   that?

Jim: It's a    2      3   my family.

Betty:Oh, can I see it?

Jim: OK!

Betty: Is this your father, Jim?

Jim: Yes,   4     5  .

Betty: And is this your   6  ?

Jim: Yes, it    7     17   . She is my mother.

Betty: And is this your   8  ?

Jim: No,   9       10  . She is my cousin.

Betty:   11   her name?

Jim: Cissy.

Betty:   12   do you   13   it?

Jim: C-I-S-S-Y.

Betty: What's   14     15   name?

Jim: White.

Betty:   16   you. Jim.

Jim:That's  OK.

螺栓拧入机体螺孔的长度为当机体为铸铁及铜时不小于1．5倍螺纹直径（）

A、1倍

B、1.5倍

C、2.5倍

D、3.5倍