Whenmakingmoderncameras,peoplebeganto_______plasticsformetal.
He works in our university as a visiting _______, not as a formal faculty member.
In the United States, the foreign policy is decided by the ________ government, not by each state.
Allthememoriesofhischildhoodhad_______fromhismindbythetimehewas65.
John _______ to be a polite man. But in fact he is veryrude.
Asateacher,youshouldnot_______thestudentsfromaskingquestionsinclass.