(+) Go Green protects the environment.(?) Does Go Green protect the environment?(-) Go Green does not protect the environment.

(+) Mary will take part in community service in Vietnam.(?) Will Mary take part in community service in Vietnam?(-) Mary will not take part in community service in Vietnam.

Students are going to donate books to children in flooded areas.(?) Are students going to donate books to children in flooded areas?(-) Students are not going to donate books to children in flooded areas.

(+) You can do volunteer work with us now.(?) Can you do volunteer work with us now?(-) You cannot do volunteer work with us now.

(-) Many people provided clothes and food for homeless people.(+) Many people provided clothes and food for homeless people.(?) Did many people provide clothes and food for homeless people?

(+) She brought some old books for poor children.(?) Did she bring some old books for poor children?(-) She did not bring any old books for poor children.

(-) Children didn't have enough food to eat.(+) Children had enough food to eat.(?) Did children have enough food to eat?

(+) Go Green has encouraged people to recycle rubbish.(?) Has Go Green encouraged people to recycle rubbish?(-) Go Green has not encouraged people to recycle rubbish.

(-) They have done volunteer work.(+) They have done volunteer work.(?) Have they done volunteer work?

(+) Sick children have to stay in the hospital all day.(?) Do sick children have to stay in the hospital all day?(-) Sick children don't have to stay in the hospital all day.

(?) Has Peter collected clothes for street kids for two years?(+) Peter has collected clothes for street kids for two years.(-) Peter has not collected clothes for street kids for two years.

(-)
(+) They should help the elderly people in their neighborhood.(?) Should they help the elderly people in their neighborhood?

(?)
(+) Volunteers often organize charity programs.(-) Volunteers do not often organize charity programs.

(-)
(+) Students can raise funds for the poor.(?) Can students raise funds for the poor?

(?) They have done volunteer work.(+) They have done volunteer work.(-) They have not done volunteer work.

(-)
(+) We should donate blood to save people's lives.(?) Should we donate blood to save people's lives?

(?) Has Peter collected clothes for street kids for two years?(+) Peter has collected clothes for street kids for two years.(-) Peter has not collected clothes for street kids for two years.

(-)
(+) People should protect the environment.(?) Should people protect the environment?

(?) Sick children have to stay in the hospital all day.(+) Sick children have to stay in the hospital all day.(-) Sick children don't have to stay in the hospital all day.