疫气通过空气和接触传染，多从()、皮肤侵入人体;也可随饮食、蚊叮虫咬、血液、或()等途径侵入人体而发病。

A. The work of the two Nobel laureates sheds light on the tiny building blocks of life-cells.
B. The work of the three Nobel laureates sheds light on the huge building blocks of life-cells.
C. The work of the three Nobel laureates sheds light on the tiny building blocks of life-cells.
D. The work of the three doctors sheds light on the tiny building blocks of life-cells.

At
B. After
C. Not until
D. Before

A. talked
B. being talked
C. talked to
D. being talked to