1. The group leader was trying to ______ his ideas clearly to his teammates.

2. Strong winds and loose rocks from recent thunderstorms have made the trail ______. Hikers are advised against climbing the mountain.

3. Please walk ______ to the class as we are going to be late for lessons.

4. James and his group members were ______ as they could not agree with one another's ideas.

5. The presenter uses the microphone to ______ his voice so that the audience in the hall can hear him clearly.