--Jack fell off the ladder yesterday, but he is all right now.
--What a lucky dog! He ______ himself badly.
| A．should injure | B． could have injured |
| C．should have injured | D．might injure |
______ she began reading and saw what fun it was, there was no stopping her.
| A．Unless | B．Once | C．Until | D．Though |
We recommend you ______ at least 15 minutes before the start of your tour.
| A．arrive | B．arrived |
| C．will arrive | D．have arrived |
I also felt guilty, as all fathers do at a time like this, wondering whether there was anything I ______ to have prevented this situation from rising.
| A．would do | B．could do |
| C．can do | D．could have done |
Children are not born with their habits already _______.
| A．to make | B．to be made | C．making | D．Made |
This is your home, _______ you may treat it as.
| A．whenever | B．whoever | C．whatever | D．Wherever |