Question

thar be a sun in the sky

1.when I was in high school ,my teacher told me that light _ faster than sound.A.traveled B.was traveling C.travels D.had traveled 2.when we got to the top of the mountain ,the sun __ in the sky.A.have visited B.would visit C.visited D .have been visiting
3.Is this the first time you _ Tokyo
A.have visited B.would visit C.visited D.have been visiting
4.the information was later admitted _from unreliable sources.A .to be retrieved B.to have been retrieved C.that it has been retrieved D.that it was retrieved

Answer 1

1、C 光比声音传播的快.这是客观真理,要使用一般现在时
2、C 主从句的时态要一致
3、A.固定句型
It is the +序数词+time that +从句（要使用现在完成时）
4、D .that it was retrieved 是the information 的同位语从句