When I saw the beautifully decorated house, I really wondered __________ she could manage that all by herself.
| A．why |
| B．when |
| C．where |
| D．how |
The first decade of the 21st century ______ breathtaking, non-stop development in China.
| A．witnesses | B．witnessed | C．will witness | D．had witnessed |
The real-name policy for train tickets has been applied to all trains since January 1,2012 in China, ______ I think will make it easy for people to get tickets.
| A．which | B．when | C．what | D．where |
His letter was so confusing that I could hardly make any ______ of it.
| A．explanation | B．meaning | C．sense | D．guess |
Today the canal is still being used. Ships can be seen moving on ______ water now and then. But it is no longer ______ busy water highway.
| A．a, the | B．the, / | C．/, a | D．the, a |
Is this the reason ________ at the meeting for his carelessness in his work?
| A．explained | B．what he explained |
| C．how he explained | D．why he explained |