As an AI language model, I don't have personal opinions, but I can provide some tips on what makes an effective public speaker for primary 7 students:

1. Confidence: An effective public speaker should be confident in their abilities and what they are saying. This can be achieved through practice and preparation.

2. Eye contact: Maintaining eye contact with the audience helps to engage them and make them feel included in the speech.

3. Clear and concise language: Using clear and concise language helps the audience to understand the message being conveyed.

4. Body language: Using appropriate body language, such as gestures and facial expressions, can help to emphasize key points and keep the audience engaged.

5. Practice: Practicing the speech beforehand can help to reduce nerves and ensure that the speaker is well-prepared.

6. Engaging content: The speech should be interesting and relevant to the audience, with a clear message or purpose.

7. Good delivery: The speaker should speak clearly and at an appropriate pace, with good volume and tone.