Getting error as unexpected identifier and error in class specification

UVM
17

hello sir
I am new to UVM
I get this error

** Error: mem_transfer.sv(2): near “uvm_sequence_item”: syntax error, unexpected IDENTIFIER

** Error: mem_transfer.sv(2): Error in class extension specification.

** Error: uvm_sequences.sv(4): near “uvm_sequence”: syntax error, unexpected IDENTIFIER

** Error: uvm_sequences.sv(4): Error in class extension specification.

** Error: mem_if.sv(4): near “#”: syntax error, unexpected ‘#’, expecting class

** Error: mem_driver_rsp.sv(3): near “uvm_driver”: syntax error, unexpected IDENTIFIER

** Error: mem_driver_rsp.sv(3): Error in class extension specification.

** Error: mem_monitor.sv(3): near “#”: syntax error, unexpected ‘#’, expecting class

** Error: mem_env.sv(2): near “uvm_env”: syntax error, unexpected IDENTIFIER

** Error: mem_env.sv(2): Error in class extension specification.

** Error: uvm_sequences.sv(3): near “uvm_sequence”: syntax error, unexpected IDENTIFIER

** Error: uvm_sequences.sv(3): Error in class extension specification.

** Error: mem_test.sv(3): near “#”: syntax error, unexpected ‘#’, expecting class

** Error: C:/questasim_10.2c/win32/vlog failed.