1.The aid agency has warned the conditions within the border camp in Mauritania are below humanitarian standards due to a lack of access to water, the extreme temperatures and regular sandstorms.

due to  由于，因為

This can be due to deviations.
這可能是由于缺陷。

a mistake due to carelessness
由于粗心而犯的錯誤

due to insufficient funds
由于經費支絀

2.A US Black Hawk helicopter has crashed in southern Afghanistan. Four soldiers are believed to have been on board. An American official said an attack could not be ruled out.

rule out  把…排除在外，排除…的可能性

Rule out neatly any words which you do not wish the examiner to read. 
整潔地劃上直線刪除你不希望主考人批閱的任何話。

Rule out that entry in the ledger, the transaction was cancelled. 
那項交易已取消了，請從分類帳上劃去那筆帳目。

He did not rule out changing his mind. 
他沒有排除改變主意的可能性。