人寿保险纯费率的计算依据是利率、（）。
A.保额损失率
B.死亡率
C.营业费率
D.附加费率
参考答案：B
—What ______ when the earthquake happened on May 12th ?
—Er, I was having a geography class in the classroom.
A. are you doing B. did you do C. were you doing D will you do
光合作用的原料是（ ）
A．淀粉和氧气
B．二氧化碳和水
C．氧气和水
D．阳光和叶绿体
