No one really knows exactly dfwhen the first people arrived in we now know as California
| A．what | B．when | C．where | D．which |
You look so tired. You _________ have stayed up again.
| A．should | B．can | C．may | D．must |
---Peter, would you like a beer to go with your meal?
---Sure, it _________.
| A．ordered | B．was ordered | C．has been ordered | D．has ordered |
_________several times, but Mary still has no idea of how to do it properly.
| A．Being shown | B．Having shown | C．Having been shown | D．I’ve shown her |
— The weather isn’t good enough for an outing, is it？
— Not in the least. We can’t have _________at this time of the year.
| A．a nicer day | B．a worse day | C．a worst day | D．so fine a day |
_________ did the students realize that they were mistaken about spiders.
| A．It was until then | B．It was not until then |
| C．Not until then | D．Not until when |