根据图画，补全对话，每空一词

1                              2

1. A:           this your          ?

   B:Yes, it is.

2.A: What's this in English?

   B: It's a          .

   A: How do you spell it?

   B: D-I-C-T-I-O-N-A-R-Y.

原人参二醇是

A．β-香树脂烷型三萜

B．α-香树脂烷型三萜

C．达玛烷型三萜

D．羊毛脂甾烷型三萜

E．甾醇类