Ababymightshowfearofanunfamiliaradult,_______heislikelytosmileandreachouttoanotherinfant.
A、ifTheproblem________whenthestudentsrefusedtodotheirhomework.
GeneralMotors,oneoftheworld'slargestautomanufacturers,isexpandingits________inthiscountry.
Whenworkersareorganizedintradeunions,employersfindithardtolaythem________.
Insomeschoolschildrenwhoprefertoreadbooksratherthan________footballbecomesocialoutcasts(被拋棄者).
Theaddressbook________theemailaddressesofyourfriendsorgroupsofcolleagues.
