The physics teacher said the earth ________ around the sun．

A.is moving

B.moved

C.had moved

D.moves

答案及解析： D

解析：

一般来说，如主句是过去时态，直接引语在变成间接引语时要注意时态的变化，即引语的时态向前提前一个时态，但当直接引语是表示客观事实或客观真理的句子时，则无须时态的变化。又如：He said that light travels much faster than sound．