Students continue to eat in school canteen______ they complain the quality of the food .

A．as though

B．even though

C．as long as

D．unless

调节胰岛素分泌的重要因素是（）

A.血糖浓度

B.内脏神经

C.胃肠道激素

D.血中游离脂肪酸

E.血中氨基酸