单项选择题 The English abstract of your thesis leaves much to be desired, so you have to rewrite it.

单项选择题 Obsessed with their research on superconductive material, they were oblivious ofthe goings-on around them.

单项选择题 Recurrent showers were forecast for the day.

单项选择题 A careful screeningof the disease will lessen the patients" anxiety.

单项选择题 Those infected with the virus of hepatitis B enjoy equal rights underthe provisions of the law.