國中英語基測出現過 on 的考題。
Balloons can be dangerous!
When balloons are let go, they are often 1 by the wind into the ocean. The salt water in the ocean washes off a balloon's color, making it look clear. Sometimes sea animals, like sea turtles, think balloons are food and eat them. The balloon can block the animal's stomach, so the animal starves to death.
We 2 hold on to a balloon and never let it fly away.