The speed of cars and trucks is ________ 30 kilometers per hour in large cities in China.
| A．limited | B．limiting | C．limiting to | D．limited to |
— I wonder ________ you’ll water this kind of flower. 
——Every other day.
| A．how often | B．how long | C．how soon | D．how much |
________ many times, he finally understood it.
| A．Told | B．Telling | C．Having told | D．Having been told |
As a new diplomat, he often thinks of_____- he can react more appropriately on such occasions.
| A．what | B．which | C．that | D．how |
—Would you please help me with the box? 
—_________
| A．Yes, please | B．No, please don’t | C．With pleasure | D．My pleasure |
David threatened_____ his neighbour to the police if the damages were not paid. 
| A．to be reported | B．reporting |
| C．to report | D．having reported |