It is most _____that the environmentalists will come to the area to investigate the possible damage caused by the serious pollution.
The little boy is dirty from head to foot because he ___ in the mud all morning.
Her ________ look suggested that she was very _______ with the answer.
This book is well worth _______. Would you like to buy one?
I have bought two ball pens , _______ writes well.
------Why do you turn back? ------ Oh, the bridge ahead_______.