Experiments of this kind ______in both the U. S. and Europe well before the Second World War.
| A．have conducted |
| B．have been conducted |
| C．had conducted |
| D．had been conducted |
I have always been honest and straightforward , and it doesn't matter_______I'm talking to.
| A．Who is it | B．who it is | C．it is who | D．it is whom |
Along with the letter was his promise ________ he would visit me this coming Christmas.
| A．which | B．that | C．what | D．whether |
The other day, my brother drove his car down the street at ________ I thought was a dangerous speed.
| A．as | B．which | C．what | D．That |
A story goes ______ Elizabeth I of England liked nothing more than being surrounded by clever and qualified noblemen at court.
| A．when | B．where | C．what | D．that |
After Yang Li Wei succeeded in circling the earth, _______ our astronauts desire to do is walk in space.
| A．where | B．what | C．that | D．How |