occur的解釋：
v.發(fā)生;出現(xiàn);存在;產(chǎn)生
第三人稱單數(shù)： occurs
現(xiàn)在分詞： occurring
過去式： occurred
過去分詞： occurred
occur的用法例句：
1. If these drugs are stopped abruptly then some withdrawal symptoms mayoccur.
如果突然停服這些藥，則可能出現(xiàn)一些戒斷癥狀。
2. Keep a pad handy to jot down queries as they occur.
手邊放一本便箋簿，以便有問題時(shí)隨時(shí)記下。
3. Nitrates are chemicals that occur naturally in water and the soil.
硝酸鹽是水和土壤中自然存在的化學(xué)物質(zhì)。
4. Emergency cooling systems could fail and a reactor meltdown could occur.
緊急冷卻系統(tǒng)有可能失靈，核反應(yīng)堆有可能發(fā)生堆芯熔毀。
5. Unless you respect other people's religions, horrible mistakes and conflict willoccur.