早在1920年,李普曼在一本著作中提出现代人与“第一手信息隔绝”的问题。这本著作是( )
A.《舆论学》
B.《自由与新闻》
C.《人民的选择》
D.《大众传播效果》
参考答案:B
It was the training _____ he had as a young man _____ made him such a good engineer.
A.what; that
B.that; what
C.that; which
D.which; that
碱式滴定管又称无阀滴定管(或皮头滴定管)。