you / volunteer / if / you / help / other / people / willingly / and / without / payment.

A. Go Green is a non-profit organization that protects the environment.

B. Go Green is a non-profit organization that protect the environment.

C. Go Green is a non-profit organization that protecting the environment.

D. Go Green is a non-profit organization that protects environment.

A. This room should be cleaned every day.

B. This room should been cleaned every day.

C. This room should clean every day.

D. This room should be clean every day.

A. You need to patient and caring when taking care of pets.

B. You need to be patient and caring when taking care of pets.

C. You need be patient and caring when taking care of pets.

D. You need to be patient and caring when take care of pets.

A. Bicycles must not be left in the hall.

B. Bicycles in the hall must not being left.

C. Bicycles in the hall must not left.

D. Bicycles must been not left in the hall.

A. My mother often donates money to charitable organizations.

B. My mother often donate money to charitable organizations.

C. My mother often donated money to charitable organizations.

D. My mother often donatees money to charitable organizations.

A. Last summer I provide English evening classes for twenty children.

B. Last summer I provided English evening classes for twenty children.

C. Last summer was I provided English evening classes for twenty children.

D. Last summer I was provided English evening classes for twenty children.