刺激胰岛素分泌的最主要因素是
A．胃泌素释放
B．迷走神经兴奋
C．血糖浓度升高
D．血氨基酸浓度升高
E．胰高血糖素释放
参考答案：C
Thanks to _____ help from his teachers and classmates, he has made _______ rapid progress in his studies.
A．不填；a
B．the; 不填
C．the; a
D．a; the
