Bob is determined to get a seat for the concert _______ it means standing in line all night for the ticket.

A．so that

B．as if

C．even though

D．however

用亲脂性有机溶剂提取总生物碱时，一般

A．先用酸水湿润药材

B．先用碱水湿润药材

C．先用石油醚脱脂

D．用正丁醇、乙醇等溶剂提取

E．用氯仿、苯等溶剂提取