I’ll never understand how it _______ that you were an hour late on such a short trip.
| A．came on | B．came about | C．came out | D．came over |
You got back so late and you didn’t even give me a proper reason _______ you hadn’t called me! I’m very unhappy with you.
| A．when | B．why | C．how | D．which |
There was a big dog ______ in front of Mr. Hill’s house, so David didn’t dare to go near it.
| A．to sit | B．sat | C．sitting | D．sits |
The tourists can not help wondering ______ the ancient people could manage to complete the magnificent building without modern equipment.
| A．that | B．how | C．where | D．what |
We have no choice. _______ we go or we stay, the result is the same.
| A．Once | B．Unless | C．Whether | D．While |
As a teacher you have to ______ your methods to suit the needs of slower children.
| A．abandon | B．apply | C．adjust | D．accelerate |