11. Scientists rely on computers to model phenomena
would
be difficult to
observe.
whereby / in case
such as / nonetheless
which / nevertheless
that / otherwise

To cite works properly, you will have to follow the respective rules depending on the style which you are citing it in.if you are having trouble properly citing works, you can use websites such as the following to you: and

In 911, a group of vikings lead by rollo besieged paris and chartres. after a victory near chartres on 26 august, charles decided to negotiate with rollo. the talks were led by hervé, the archbishop of reims. this resulted in the treaty of saint-clair-sur-epte, which granted rollo and his soldiers all the land between the river epte and the sea. it also granted him brittany, "for his livelihood". at the time, brittany was an independent land which france had not been able to conquer. in exchange, rollo promised the king his loyalty and military assistance when needed. also rollo also agreed to be baptised and to marry gisela, the king's daughter. the territory given rollo is about the same as upper normandy.

Ibelieve that it would be b because its the one that sounds the most correcttell me if you get it right : )