1. The problem is to choose the correct verb form in each sentence to match the subject. 2. The rule is that singular subjects take singular verbs, and plural subjects take plural verbs. 3. Sentence 1: "The exhibit of the artist's paintings (was/ were) very interesting." - "Exhibit" is singular, so the correct verb is "was". 4. Sentence 2: "Every one of the girls (do/ does) her shorthand homework." - "Every one" is singular, so the correct verb is "does". 5. Sentence 3: "Either Julia or her friends (is/ are) planning to attend." - When subjects are joined by "either...or", the verb agrees with the nearer subject. - "Friends" is plural, so the correct verb is "are". 6. Sentence 4: "One of the students (is/ are) studying martial arts." - "One" is singular, so the correct verb is "is". 7. Sentence 5: "A little practice in the evenings (help, helps) us play better." - "Practice" is singular, so the correct verb is "helps". Final answers: 1. was 2. does 3. are 4. is 5. helps