VSCode can't find pkgs

When I typed the code below in VSCode on MacOS10.14.5, it seems that VSCode can’t find the standard library of Julia. But I can use the pkgs in the REPL, and I can also run the file successfully.

How can I fix this problem? I have already set the Executable Path in VSCode to be “/Applications/Julia-1.2.app/Contents/Resources/julia/bin/Julia”.
Thanks for your help.

Hm, that is weird, I can’t replicate that here on my system…