occasion怎么确定单复数的形式呢?

<p>occasion的用法</p><p>1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [C] particular time ( at which an event takes place ) （事情发生的）时刻，时候，场合&nbsp;</p><p>2.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; on this / that occasion&nbsp; 此时 / 彼时&nbsp;</p><p>3.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; on the present occasion 在这次&nbsp;</p><p>4.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; on one occasion = once 有一次&nbsp;</p><p>5.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; on rare occasions 偶尔&nbsp;</p><p>6.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;I’ve met him on several occasions.&nbsp; 我见过他几次。</p><p>7.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; I was not at home on that occasion. 那时我正好不在家。</p><p>8.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; I only wear a tie on special occasions. 我只在特殊场合才打领带。</p><p>9.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; On one occasion he even rang me in the middle of the night. 有一次他甚至在午夜给我打电话。</p><p>10.&nbsp;&nbsp; On this occasion, as it happens, the engine started immediately.</p><p>11.&nbsp;&nbsp; 2. suitable time for sth. ; opportunity&nbsp; 时机；机会</p><p>12.&nbsp;&nbsp; You should go there if the occasion arises. 如果有机会，你应当到那里去。</p><p>13.&nbsp;&nbsp; He used the occasion to express his gratitude.&nbsp; 他利用那机会表达了感激之情。</p><p>14.&nbsp;&nbsp; 3. [ C ] special event or celebration&nbsp; 特殊的事件或庆典&nbsp;</p><p>15.&nbsp;&nbsp; &nbsp;The wedding was quite an occasion. 该婚礼是一盛会。</p><p>16.&nbsp;&nbsp; 4. [ U ] 原因；理由；需要&nbsp; I’ve had no occasion to visit him recently.</p><p>17.&nbsp;&nbsp; 我最近无需去看他。&nbsp; You have no occasion to be angry. 你没有理由生气。</p><p>18.&nbsp;&nbsp; There was no occasion to be so rude. 没有理由这样粗鲁。 5. 习语 a sense of occasion 场合意识 on occasion(s) 偶尔；必要时 on the occasion of her daughter’s wedding 在她女儿的婚礼上 e.g. He wore shabbiest clothes to the party: he hads no sense of occasion.他穿着最寒酸的衣服去参加聚会，毫无场合意识。 He has even been known to go shopping himself on occasion. 6. 区分： condition 指某时某处事情发展、存在的状况、状态，一个人的&quot;感觉如何&quot;。 situation 往往指一组情况或一些情况的综合。常译为&quot;情况&quot;、&quot;形势&quot;。 occasion 指某事发生的时刻或社交上从事某活动的合适的&quot;时机&quot;、&quot;场合&quot;、&quot;良机&quot;。 opportunity 指有做某事所必需的实际环境。 chance 指偶然的机会，也可指可能性。 e.g. I took the opportunity of visiting my aunt while I was in Beijing. 我利用在北京的机会探望了我的姨母。 Chances are that you will be promoted. 你很可能晋升。 7. occasion 作先行词，定语从句引导词： 如果occasion表示机会, 时间的话 就用when引导。 eg. Occasions are quite rare when I have the time to spend a day with my kids. 如果它翻译成场合，表示地点, 就用where引导。 eg. This is not an occasion for laughter, where you must take things seriously.&nbsp;</p><p><br ></p>