Halley made his discovery （）

单项选择题When the baby was first sent to the hospital in London, her illness was considered to be （）

A．quite easy to treat
B．the result of thallium poisoning
C．a common one
D．extraordinarily serious

单项选择题As far as we can tell from the story, Agatha Christie （）

A．had never met this baby
B．had spent a long time studying the baby' s illness
C．visited the baby both in Deleville and London
D．gave the nurse some advice on, the telephone