1.Inmyopinion/view,Ibelieve/consider/thinkthat...
在我我认为/考虑/认为...
2.Thereareseveral/fewfactors/causes/reasonsthatcontributeto/leadto...
有几个/几个因素/原因是导致/导致...
3.Itiswidely/generally/commonlyknown/accepted/acknowledgedthat...
这是广泛/普遍/通常/被承认...
4.Therefore,itisessential/crucial/vital/importantto...
因这是必需/至关重要/至关重要/重要...
5.Asaresult/consequence,wecanconclude/infer/deducethat...
果/果是我们可以得出论/推断/推论...