20150914【每日口說練習】(gas)

When this gas wafts into your eyes,
certain neurons instruct your tear ducts
to flush out this potentially harmful substance.

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waft
A breeze wafted the music across the lake.
A scent of lemon wafted up from the garden below.

neuron

duct

harmful
Smoking is harmful to health.

flush out

instruct
He instruct me to deliver it to a customer.
My job is to instruct her in English.
My agent has instructed me that you still owe me $120.


substance
Ice and snow are different forms of the same substance,water.
The substance of his speech was that he was better than other candidates.