I was walking in the street yesterday _____ I met with our football coach.
| A．before | B．when | C．until | D．since |
Some pictures of the river brought the days back to the old ________ they swam in it.
| A．when | B．that | C．who | D．where |
Is this research center ________ you visited the modern equipment last year?
| A．where | B．that | C．the one that | D．the one where |
The humans are destroying nature day by day, ________ of course, will cause severe punishment from it sooner or later.
| A．who | B．when | C．on which | D．which |
The people, ________ had been damaged by the flood, were given help by the Red Cross.
| A．all whose homes | B．all of whose homes | C．all their homes | D．all of their homes |
There is no such place ________ you dream of in all this world.
| A．that | B．what | C．which | D．as |