Replace the underlined part in each of the following sentences with a word or phrase from the five expressions below. Write your answer in the brackets. Make changes or additions where necessary. elusive; as yet; in its entirety; expertise; imperative; (1) It is extremely important, necessary and urgent for us to change our way of thinking or we will be out of step with(与...脱节) our times. ( ) (2) The document needs to be read and understood as a whole . ( ) (3) An agreement to end the fighting remains difficult to achieve . ( ) (4) We have the resources as well as the special knowledge and skills to finish the project. ( ) (5) There are no details of plane crash available so far . ( )