Roses are quite _____ flowers in English gardens.
| A．ordinary | B．common | C．usual | D．general |
At minus 130℃, a living cell can be ______ for a thousand years.
| A．spared | B．protected | C．preserved | D．developed |
The traditional view is ______ we sleep because our brain is “programmed” to make us do so.
| A．when | B．why | C．whether | D．that |
______ he referred to in his article was unknown to the general reader.
| A．That | B．What | C．Whether | D．Where |
Small sailboats can easily turn over in the water ______ they are not managed carefully.
| A．though | B．before | C．until | D．if |
His movie won several awards at the film festival, ______ was beyond his wildest dream.
| A．which | B．that | C．where | D．it |