我是 Ruby 的新手，我完全不知道如何解决我收到的这个错误。如果有人能解释什么是错误，那就太棒了。
Traceback (most recent call last):
21: from bin/rails:4:in `<main>'
20: from bin/rails:4:in `require'
19: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands.rb:16:in `<top (required)>'
18: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/command.rb:44:in `invoke'
17: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/command/base.rb:63:in `perform'
16: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/thor-1.1.0/lib/thor.rb:392:in `dispatch'
15: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/thor-1.1.0/lib/thor/invocation.rb:127:in `invoke_command'
14: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/thor-1.1.0/lib/thor/command.rb:27:in `run'
13: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:130:in `perform'
12: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:130:in `tap'
11: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:133:in `block in perform'
10: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:133:in `require'
9: from D:/[Dearest_Lord_God,_please_intuitively_reveal_the_things_that_used_to_baffle_me]/[Projects-React]/rails-react/open-flights/config/application.rb:7:in `<top (required)>'
8: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler.rb:174:in `require'
7: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:58:in `require'
6: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:58:in `each'
5: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:69:in `block in require'
4: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:69:in `each'
3: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:74:in `block (2 levels) in require'
2: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:74:in `require'
1: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/pg-0.19.0-x64-mingw32/lib/pg.rb:4:in `<top (required)>'
C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/pg-0.19.0-x64-mingw32/lib/pg.rb:4:in `require': cannot load such file -- pg_ext (LoadError)
22: from bin/rails:4:in `<main>'
21: from bin/rails:4:in `require'
20: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands.rb:16:in `<top (required)>'
19: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/command.rb:44:in `invoke'
18: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/command/base.rb:63:in `perform'
17: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/thor-1.1.0/lib/thor.rb:392:in `dispatch'
16: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/thor-1.1.0/lib/thor/invocation.rb:127:in `invoke_command'
15: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/thor-1.1.0/lib/thor/command.rb:27:in `run'
14: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:130:in `perform'
13: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:130:in `tap'
12: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:133:in `block in perform'
11: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb:133:in `require'
10: from D:/[Dearest_Lord_God,_please_intuitively_reveal_the_things_that_used_to_baffle_me]/[Projects-React]/rails-react/open-flights/config/application.rb:7:in `<top (required)>'
9: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler.rb:174:in `require'
8: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:58:in `require'
7: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:58:in `each'
6: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:69:in `block in require'
5: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:69:in `each'
4: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:74:in `block (2 levels) in require'
3: from C:/Ruby27-x64/lib/ruby/2.7.0/bundler/runtime.rb:74:in `require'
2: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/pg-0.19.0-x64-mingw32/lib/pg.rb:3:in `<top (required)>'
1: from C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/pg-0.19.0-x64-mingw32/lib/pg.rb:14:in `rescue in <top (required)>'
C:/Ruby27-x64/lib/ruby/gems/2.7.0/gems/pg-0.19.0-x64-mingw32/lib/pg.rb:14:in `require': cannot load such file -- 2.7/pg_ext (LoadError)