Two years ___ he began to write another story-book. [ ]

A. after

B. later

C. in

D. late

不宜用于判断幽门螺杆菌根除疗效的检测方法是()

A．尿素酶法

B．组织切片染色法

C．细菌培养法

D．13C-或14C-尿素呼气试验

E．血清抗幽门螺杆菌抗体检