"Class" in sentence "We didn't know it then, but those days were the start of a separation between us. Related by blood, my father and I are separated by class. I am the white-collar son of a blue-collar man." means ______.
A.
a group of students graduating together
B.
a period of time during which students are taught
C.
a group of persons who have the same social position and rank
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
皮皮学刷刷变学霸
举一反三
【简答题】用 0.01EDTA 标准溶液滴定等浓度的 Ca 2+ 溶液,问在 pH=5.0 的条件下, K ‘ CaY 为多少?能否准确滴定 Ca 2+ ?若要准确滴定 Ca 2+ ,则允许的最低 pH 值为多少? ( pH=7.0 , lgα Y(H) =3.32 ; pH=8.0 , lgα Y(H) =2.27 )