_________ environmental damage is done, it takes many years for the ecosystem to recover.
| A．Even if | B．If only | C．While | D．Once |
—Mary, new copies of Harry Potter are on __________ now.
—Great! Let's go and buy one this afternoon.
| A．sale | B．holiday | C．condition | D．rise |
The tall buildings are _________ in the lake aroundwhich there are many trees.
| A．reflected | B．reflecting | C．standing | D．stood |
He had been so absorbed __________ watching the carpassing by that he didn't notice his friends __________.
| A．to；coming | B．in；to come | C．on； coming | D．in； coming |
According to a UN report, some 844 animals and plants __________ in the last 500 years.
| A．disappeared |
| B．were disappeared |
| C．have disappeared |
| D．had been disappeared |
—Have you finished the book? —No. I've read up to __________ the children discover the secret cave.
| A．which | B．what | C．that | D．where |