Where is the ethernet frame FCS filed?

Hi, all

Ethernet frame is composed of several field

Dest. mac address¡BSrc. mac address
Length/Type ¡BMac client data ¡BPad ¡BFCS (trailer)

But I use Wireshark to capture my packet that from

my pc to gateway.

And I observed the result, finding that

there is not FCS field in each ethernet frame sometimes.

A few ethernet frame with FCS field.

What happened???
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