Ozone is formed when an electric spark is passed through oxygen.电火花遇到氧气会产生臭氧。He passed an electric spark through a mixture of gases.他让一束电火花穿过了一团混合气体。Close the circuit and you'll see a blue spark.接通电路你就会看到一个蓝色的电火花。A spark ignites the stove's burner.电火花点着了厨灶煤气头。