was the plan difficult to carry out,it was dangerouswas the plan difficult to carry out,it was dangerous .空格填甚麼连词

was the plan difficult to carry out,it was dangerous
was the plan difficult to carry out,it was dangerous .空格填甚麼连词

Was the plan difficult to carry out, as/since it was dangerous.
执行此项任务是否很困难,因为它很危险.

so what ?
是要翻译还是怎样？