The Customs have discovered a large amount of illegal drugs?

[Maggie]

Hi, guys

1. The Customs have discovered a large amount of illegal drugs last Friday.

2. The Customs have found a large amount of illegal drugs last Friday.

3. The Customs have discovered a large amount of Heroins last Friday.

Could you check out all of them are correct or not for me?

Thank you so much.

Maggie
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[Molly]

1. The Customs have discovered a large amount of illegal drugs last Friday. (No. "Last Friday" cannot be used with "have found". Use the past simple instead. "Discovered" is OK.)

2. The Customs have found a large amount of illegal drugs last Friday. (No. "Last Friday" cannot be used with "have found". Use the past simple instead. "Found" is OK.)

3. The Customs have discovered a large amount of Heroins last Friday. (No. "Last Friday" cannot be used with "have found". Use the past simple instead. And "heroin" is OK, not "heroins")

Try:

The Customs discovered/found a large amount of illegal drugs last Friday.

Or this:

Last Friday, the Customs discovered/found a large amount of illegal drugs.

NB I would probably write "Customs discovered/found..." or The customs office discovered/found...", and not "The Customs discovered/found...".