---- __________ you say goodbye so soon?
---- I’m sorry. My mother is expecting me at home.
| A．Must | B．Can | C．Would | D．Might |
Teenagers ________ their health because they play computer games too much．
| A．have damaged |
| B．are damaging |
| C．damaged |
| D．will damage |
Peter’ shirt looked just the same as Tom’s，but it cost ______ his．
| A．as much twice as |
| B．twice as much as |
| C．much as twice as |
| D．as twice much as |
We can’t figure out ______ quite a number of insects and birds are dying out．
| A．that | B．as | C．why | D．when |
______ environmental damage is done，it takes many years for the ecosystem to recover．
| A．Even if | B．If only |
| C．As if | D．Once |
Spending a few hours learning about the history and culture of the destination will help tourists understand they're seeing
| A．what | B．where |
| C．that | D．why |