When you come into the exhibition hall，you can see a large board with a notice on it，saying visitors__________not to touch the exhibits.
| A．will request | B．request |
| C．are requesting | D．are requested |
______________ with the sun, the earth is not big at all.
| A．Comparing | B．Compared | C．To compare | D．Compare |
The little boy is dirty from head to foot because he ___ in the mud all morning.
| A．has played | B．is playing | C．has been playing | D．was playing |
Her ________ look suggested that she was very _______ with the answer.
| A．satisfying；satisfied | B．satisfied；satisfying |
| C．satisfied； satisfied | D．satisfying；satisfying |
This book is well worth _______. Would you like to buy one?
| A．to read | B．being read | C．reading | D．to be read |
I have bought two ball pens , _______ writes well.
| A．none of them | B．neither of them | C．neither of which | D．none of which |