补全对话。

A: Hi, Sam! Come here, Let’s    1    basketball.

B:     2    , I can’t.

A: What are you    3    now?

B: I am    4     my homework. Go and    5    David.

A: Thank you.     6     is he?

B: He is     7     home.

A: Is David in?

C: Yes, come    8     , please.

A: David,    9    you like to go and play basketball    10    us?

C: Certainly! Please sit here. Just a minute. Let’s go.

人体内嘌呤核苷酸分解的终产物是（）。

A.尿素

B.尿酸

C.肌酸

D.肌酐

E.甘氨酸