注 æ: beforeå¯ä½ä»è¯ï¼åæ¥æ¶é´ç¹ï¼ä¹å¯ä½è¿è¯ï¼å¼å¯¼æ¶é´ç¶è¯ä»å¥ãèagoä¸è½ç¨ä½ä»è¯åè¿è¯ã He will be back before five oâclock. ä»ä¼å¨äºç¹é以ååæ¥ã Iâll ring you up before I leave home. æ离家以åå°ç»ä½ æçµè¯ã