A:His name is Bob.
B:Hi, my name's Bob.
C:This is my classmate.
—Our class will have a party the evening of June 30th. Would you like to come? —Yes, I'd love to, but I'm going to visit my grandparents in Dalian.
总和生育率是按照某一年度的妇女生育水平,计算每个妇女度过其整个生育期可能生育的子女数。下图表示1950—1996年我国总和生育率变化情况,读图回答下列问题。