求翻译：二月选封面是要参加新加坡亚太海事展（封面已售出），四月参加南京国际船舶工业博览会and上海国际钢管展，十月是因为参加大连国际海事展览会and舟山国际海洋工程技术装备展览会是什么意思？

February election is to cover Asia Pacific Maritime, Singapore (cover sold), April to participate in Nanjing International Exhibition and Shanghai International Shipbuilding Industry Exhibition pipe, because in October to participate in Zhoushan, Dalian International Maritime Exhibition and Internat

It is necessary to participate in elections in February cover Singapore asia pacific maritime exhibition (cover) have already been sold in April, participate in Nanjing and Shanghai International Industry Fair International Ship pipe exhibition in October, because of their participation in the Dalia

In February chooses the title page is must participate in the Singapore Asian and Pacific maritime affair to unfold (title page to sell), in April participates in the Nanjing international ships industry exposition and Shanghai international steel pipe to unfold, October is because attends the Dalia

Cover February elections were to take part in Singapore Asia Pacific maritime exhibition (covers were sold), in April at Nanjing international steel tube industry Expo and Shanghai International ship show, October is due to their participation in the Dalian international maritime exhibition and Zhou

Select the front cover to participate in the exhibitions (front cover has already been sold) of Asian-Pacific maritime affairs of Singapore in February, participate in the exhibition of international steel tube of industrial exposition and Shanghai of international shipping of Nanjing in April, part