JohnLogieBairdconstructedthefirstcolorTVin1928,butitwa...

問題詳情：

 John Logie Baird constructed the first color TV in 1928, but it was not until 1938 _________ the first color TV program was broadcast.

  A. which          B. that             C. when             D. who

【回答】

B

知識點：強調句

題型：選擇題