．________ useful book is helpful to ________ artist.
| A．An, an | B．A, a | C．A; an | D．An; a |
Mount Wuyi is such an attractive place of interest ________ everyone likes to visit.
| A．that | B．as | C．which | D．what |
The boy burst into tears ________ he saw his mother.
| A．at the moment | B．in a moment | C．for a moment | D．the moment |
Raising environmental awareness was the aim of our art exhibition ____ last week.
| A．to hold | B．held | C．having held | D．being held |
_________ he was, he still went on with his work.
| A．Tired although | B．Tiring as | C．Tired though | D．While tired |
It is ten years since we ________ each other last time．
| A．see | B．have seen | C．saw | D．had seen |