（1）-------,scientists say,there would not be too much wastag

1.Apparently,意思是表面上显然,强调抽象意义的”显然“.
如：
1）Apparently they're intending to put up the price of water.
看来他们要提高水费了.
2）Apparently he never wrote a letter to her.
显然,他一封信也没给她写.
2.Noticeably,意思是“显著地,明显地”,强调“跟……相比很显著,很明显”.
例如：
1) His white hair was very noticeably different from his dark skin.
他的白头发与黑皮肤形成了鲜明的对比(强调黑、白比较）.
2）I am starting to bald noticeably.
我头顶明显地开始变秃了（强调跟原来比较）.
3.Notably,意思是显著地,值得注意地,特别地.强调“特别地“,意思与especially近似.
例如：
1） Many students were absent,notably the monitor.
许多学生缺席,特别是连班长也没来（强调“特别是,尤其是”）.
4.Distinctly,强调”清晰地,清楚地“.
例如：
1）He spoke very distinctly.
他说话十分清晰.
2）A distinct heading which is distinctly and totally relevant to the data being sought.
一种明显清晰的标题,这种标题很明确,完全与被寻找的数据有关.
第二个问题,原句的意思是这个引起争论的问题不是我们该不该做而是我们能不能做.
argumentative指”爱争论的,好辩论的“,controversial指”有争议的,引起争论的“,debate是名词或者动词,表示”辩论,争论“,disputable表示”有争议的,可疑的“.ABD为形容词,但B意思正确；C词性不符.
希望对你有所帮助.