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
If you stick to it, this plan ______ that your company is well prepared to deal with future challenges.
A．ensured B．will ensure C．ensures D．would ensure
