“Apple,pear,peach,orange,lemon,etc.”makeupthe______of“fruit”.

Johnsonwas________unknownbeforerunningforthepresidency.

Acompoundisthecombinationofonlytwowords.

Accordingtothe"principles-and-parameters"theory,"principles"refertohighlyabstractpropertiesofgrammarwhichareappliedtolanguageingeneralandwhichgeneratephrasesandatthesametimerestrainthepowerofMovea,while"parameters"allowgeneralprinciplestooperateincertainrestrictedways,accordingtowhichparticulargrammarsofnaturallanguagesvary.

Amongthefollowingwords,“______”containsanegativeprefix.