Word FormationEsercizio 79 di 114

Penguins are (0) FLIGHTLESS (FLIGHT) birds which live south of the Equator. As their legs are short, they (1) .......... (USUAL) stand upright and walk when they are on land. When they find it (2) .......... (NEED) to travel at greater speed, they often drop on to their stomachs and slide along. But it is at sea…