Question

—        is your sister?
—She is eight years old.

A．How	B．How old
C．What	D．Where

Answer 1

B

考查疑問詞。How怎樣，How old 多大，What什么，Where在哪兒。根據(jù)答語內(nèi)容She is eight years old.可知上文問的是年齡，故選B。