1.(+) Go Green protects the environment.
(-) Go Green doesn't protect the environment
(?) Does Go Green protect the environment?
2.(+)Many people provided clothes and food for homeless people.
(-) Many people didn't provide clothes and food for homeless people.
(?) Did many people provide clothes and food for homeless people?
(?)Has Peter collected clothes for street kids for two years?
(-) Peter hasn't collected clothes for street kids for two years.
(+) Peter has collected clothes for street kids for two years.
$\text{CHÚC HỌC TỐT!!}$