It was not until 1938 the first colour TV programme was broadcast.A. whichB. thatC. whenD

问题补充：

It was not until 1938 the first colour TV programme was broadcast.

A. which

B. that

C. when

D. on which

答案：

A. which

(答案→)B. that

C. when

D. on which

解析：考查强调句型。本题是强调句型，强调句型的基本结构为It is/was被强调成分that/who其它成分；其最大的特点就是去掉it is/was…that/who…句子仍然成立。要注意强调句型能强调除谓语动词以为的所有的句子成分。在考查的时候，经常会把强调句型和定语从句结合在一起考查，要注意分析句子的成分。本句强调的是时间状语not until 1938；句意：直到1938年，第一档彩色的电视节目才被播放。故B正确。