Basic questions about D lang?

[Jayam via Digitalmars-d-learn]

In D lang,
1. Is there any feature async/ await like "c#" ? I can't find 
feature like async.
2. Is Garbage Collector work default without any code to force 
like in c# or do we need to manually trigger it ?
3. Can we make library file and use that in any project like 
'Util class' ?