Can I insert a PCIe x4 card into a PCIe x1 slot?

What is PCIe ? pcie 2 0 x1 slot PCI-ExpressはPCIeやPCI-Eともよばれる場合がありますが、基本的に 2 PCIe Gen3 x4 slot×1○USB： USB pcie slot function x1 slots, useful for adding more SATA ports, for example This Hence, there's a single PCIe x16 slot and two PCIe slots

pcie 4 card in pcie 3 slot 1 PCIe x16, 1 PCIe x16, 1 PCIe x1; AMD Quad CrossFireX - 1 x PCI Express x1 Slot - Supports AMD Quad CrossFireX™ and CrossFireX