Well, say the question aloud and try to figure it out. <em>.....if he found the overdue library book, or didn't he look </em>.....if he found the overdue library book , but didn't he look? .....if he found the overdue library book, and didn't he look?
I think that personally, or fixes that up pretty good. ;) From one Smartie <em /> to another- BubbleSmartie11
Is - two billion dollars is a unit, one unit so it is singular and you use the singular verb think - scientists is a plural, therefore, you must use the plural verb form of think
