How Hydroxyapatite Toothpaste Compares With Fluoride for Oral Health

Study the questions and tasks

Work through the material below, or start the interactive practice above to complete an attempt. Try the exercises before opening any answer or transcript sections, then use them to review your work.

Practice level

C1. Try this level if you can follow the instructions and understand most of the language; choose an earlier level if you need more support.

Question formats

Fill in the blank (dropdown)

How to approach this practice

Read the complete sentence and notice the subject, verb form, time reference and word order before answering.

1. Question 1 · Fill in the blank (dropdown)

   Choose the correct option for each blank.

   Although interest in hydroxyapatite is growing, experts ___ that fluoride remains important.

   Choices for blank 1

   1. emphasize
   2. emphasizes
   3. emphasizing
   4. to emphasize
   Check answers and explanations

   Blank 1

   emphasize

   The plural subject “experts” requires the present-tense plural verb.

2. Question 2 · Fill in the blank (dropdown)

   Choose the correct option for each blank.

   Fluoride products became common and ___ widely available around the world.

   Choices for blank 1

   1. subsequently became
   2. subsequently become
   3. subsequently becoming
   4. subsequently to become
   Check answers and explanations

   Blank 1

   subsequently became

   The coordinated past-tense verbs describe completed historical developments.

3. Question 3 · Fill in the blank (dropdown)

   Choose the correct option for each blank.

   The evidence does not establish that every hydroxyapatite product ___ identically.

   Choices for blank 1

   1. performs
   2. performing
   3. to performs
   4. performed to
   Check answers and explanations

   Blank 1

   performs

   After “establishes that,” the plural subject takes the base-form verb.

4. Question 4 · Fill in the blank (dropdown)

   Choose the correct option for each blank.

   Consumers should evaluate whether product claims ___ by reliable evidence.

   Choices for blank 1

   1. are supported
   2. is supported
   3. supporting
   4. to be support
   Check answers and explanations

   Blank 1

   are supported

   The passive construction requires the plural auxiliary “are.”

5. Question 5 · Fill in the blank (dropdown)

   Choose the correct option for each blank.

   Tenuta links oral health with microorganisms in the mouth, systemic health, and ___ of the gut microbiome.

   Choices for blank 1

   1. the composition
   2. a composing
   3. compose
   4. to composition
   Check answers and explanations

   Blank 1

   the composition

   The parallel noun phrase requires the definite article before “composition.”

6. Question 6 · Fill in the blank (dropdown)

   Choose the correct option for each blank.

   The article recommends that consumers ___ product claims carefully.

   Choices for blank 1

   1. assess
   2. assesses
   3. assessing
   4. to assessed
   Check answers and explanations

   Blank 1

   assess

   Mandative subjunctive clauses use the base form after “recommends that.”

7. Question 7 · Fill in the blank (dropdown)

   Choose the correct option for each blank.

   ___ the growing interest, the article does not claim that hydroxyapatite should replace fluoride automatically.

   Choices for blank 1

   1. Despite
   2. Although
   3. Because of that although
   4. Despite of
   Check answers and explanations

   Blank 1

   Despite

   A concessive preposition correctly introduces the noun phrase “the growing interest.”

What to review next

After checking an answer, explain the rule in your own words and write a new sentence using the same pattern. Revisit any rules you could not explain.

A focused practice result shows how you did on these tasks. Use several activities across skills to decide what to study next; one practice score does not certify an overall CEFR level.