液化烃储罐成组布置时，应符合哪些防火规定？其防火堤如何设置？
空心板有哪些优点？
All coast radio stations（）DSC installed for VHF and HF. ["have","had","are having","have had"]
The vessel has stayed in port for seven days because she needs（）. ["repairs","repairing","repaired","being repaired"]
可燃液体的地上储罐成组布置时应符合哪些防火规定？罐组总容积和个数应符合哪些规定？
槽形板优点和缺点各是什么？
