add to增加,增添,补充

例句：Hops also contain tannins, which add to beer color.
      它还含有能增进啤酒色泽的单宁。

2.Using dead reckoning near the southern most area of South America called for an expert.

call for要求,需要,号召

例句：Our agency agreement calls for a timely market report.
      我们的代理协议要求你方及时递交市场报告一份。

3.Perhaps no other captain sailing at that time would think to have a woman do this extremely important work.

no other没有别的

例句：The facts admit no other explanation.
      这些事实不容有其他解释。