3. The people thought a lion/loin was nearby 4 Her voice faltered, and had no effect/affect on Tansen's body
5. Can you insure/ensure that he attends the ceremony
6 A foreword/forward is a short introductory statement in a book, which is written by
someone other than the author​

3. Lion.

4. Effect.

5. Ensure.

6. Foreword.

Explanation:

The question requires that the most appropriate word is chosen or selected among the list of words provided in each sentence.

1. The people thought a lion was nearby. Lion is a wild animal popularly referred to as the king of the jungle while loin refers to the lower part of the abdomen, reproductive organ or groin. Therefore, lion is the most appropriate choice.

2. Her voice faltered, and had no effect on Tansen's body. Effect is the direct result or outcome of an action (cause) while affect is to change, alter or influence a thing. In this context, the most appropriate word choice is effect.

3. Can you ensure that he attends the ceremony. Ensure is to guarantee or endeavor that an action is performed while insure is a form of compensation provided in the event of a loss based on an agreement. In this case, ensure is the most appropriate.

4. A foreword is a short introductory statement in a book, which is written by

someone other than the author. Forward simply means to advance in a frontal direction.