📘elementary (基础的)

She gave an elementary explanation of the problem.

He learned elementary mathematics in school.

A boy enters a science fair at his elementary school

A boy enters a science fair at his elementary school with a homemade volcano project

A boy enters a science fair at his elementary school with a homemade volcano project that he built using cardboard, paint, and baking soda

A boy enters a science fair at his elementary school with a homemade volcano project that he built using cardboard, paint, and baking soda and he demonstrates how the eruption works

A boy enters a science fair at his elementary school with a homemade volcano project that he built using cardboard, paint, and baking soda and he demonstrates how the eruption works by adding vinegar to create a fizzy reaction

A boy enters a science fair at his elementary school with a homemade volcano project that he built using cardboard, paint, and baking soda and he demonstrates how the eruption works by adding vinegar to create a fizzy reaction while explaining the science behind real volcanoes

A boy enters a science fair at his elementary school with a homemade volcano project that he built using cardboard, paint, and baking soda and he demonstrates how the eruption works by adding vinegar to create a fizzy reaction while explaining the science behind real volcanoes and the judges are impressed by his clear presentation

A boy enters a science fair at his elementary school with a homemade volcano project that he built using cardboard, paint, and baking soda and he demonstrates how the eruption works by adding vinegar to create a fizzy reaction while explaining the science behind real volcanoes and the judges are impressed by his clear presentation so they award him first place in his age group

A boy enters a science fair at his elementary school with a homemade volcano project that he built using cardboard, paint, and baking soda and he demonstrates how the eruption works by adding vinegar to create a fizzy reaction while explaining the science behind real volcanoes and the judges are impressed by his clear presentation so they award him first place in his age group and his project is displayed at the front of the school for a whole week.