The _______ income of the common people has been greatly increased in the past thirty years ______ the reform and opening-up policy in China.

A．regular; because

B．usual; thanks to

C．normal; on an account of

D．annual; owing to

典型的十二指肠溃疡的症状特点是（）。

A.进行性吞咽困难

B.进餐后上腹痛，至下一餐前缓解

C.不洁饮食后上腹痛，伴呕吐、腹泻

D.空腹及夜间上腹痛，进食后可缓解

E.反酸、烧心伴胸骨后烧灼样痛