What is the definition of subject–verb agreement?

Correct my question my english is not good: “what the effect and the effectiveness of strength exercise in breast cancer medication related to lymphedema? ”

Read this passage: i think of you daily, my darling, especially when it’s dark and the other men in the foxhole become silent. i like to pretend that the gunfire is a fireworks display and that you are here with me to enjoy it. who is the intended audience for this passage? a. the writers girlfriend at home b. the writers fellow soldiers c. the writers mother and father d. the writers commanding officer

Select the indicate quotation that correctly sequences the verbs