Theaddressbook________theemailaddressesofyourfriendsorgroupsofcolleagues.
A、makesiteasytorecallItisusefultoscience_______theearthasanobjectinspace.
Shehadclearlyno________ofdoinganywork,althoughshewasverywellpaid.
Thefarmerhadtowearheavybootsinthewinterbecausethefieldsweretoowetand________.
Whenhesuddenly________upthesubjectofgeneticengineering,therewasanembarrassedsilence.
Becareful,_______you'llfalldown.
