However, ___________ the technological difficulties of preparation, this material affords a further wide field of application(用途).
There was ___ knock on ___ door. I opened it and found __ small dark man in ___ rags.
---Where’s Jack? ---I think he’s still in ___ bed, but he might just be in ___ bathroom.
Alexander Graham Bell invented ___ telephone in 1876.
He has got used to sleeping in ___daytime and working at ___ night.
Write ___ “s” here and write ___ “h” there, please.