Chose the best option to complete the sentence

Chose the best option:A,B,C,D to complete the sentence
19/ We sometimes                      out when we lived in the city
A.Eat       B.Will eat    C.Have eaten       D.Ate
20/ Vinh                     home for school yet
A.Didn't leaver    B.Hasn't  left         C.Isn't leaving    D.Don't leave 
21/ They would like some vegetables, some meat and some rice                 dinner
A.For         B.From       C.In     D.At
22/ Is the Nile River                  river in the world ?
A. Long    B.Longer       C.Longest      D.The longest
23/ A hi - tech robot will helps us                children while we are away
A.Look out     B.Look at      C.Look after        D.Look in