Everyone wants to live in a beautiful，comfortable and livable place，but not ________ know where it is.
| A．all | B．some |
| C．either | D．both |
______ was most shocking about the tornadoes in America was that they threatened six states and killed more than 100 persons.
| A．That | B．Which | C．Why | D．What |
The disappearance of dinosaurs made _______ the evolution and dominance of mammals on the earth.
| A．it was possible | B．it possible | C．possible to be | D．possible |
I felt most angry about the way ______ I was treated when I was shopping.
| A．when | B．that | C．which | D．where |
Regarding China-US differences on human rights issues, Hong said the two sides can enhance mutual understanding through dialogue ______ on equality and mutual respect.
| A．based | B．to base | C．basing | D．base |
When we start gazing into the night sky with a telescope, soon we’ll be astonished by the realization _______ we and our world are part of this giant system.
| A．which | B．whether | C．that | D．as |