a. 有两边的, 双边的, 双方的【医】 两侧的

◆记忆方法一：
bi做为前缀表示“两，双”，lateral表示“侧面的”

multiply/multilateral/multi-polar/unilateral/bilateral
记忆：
1. 前缀multi-表示“多”，词根ply表示“折”，multiply [ 5mQltipli ] v. 繁殖, 乘 Five multiplied by four is twenty. 五乘以四等于二十。
2. 词根later表示“边”，multilateral [ 5mQlti5lAtErEl ] adj. 多边的 A multilateral conference will be held to discuss the nuclear control. 他们将举行多边会议来讨论核控制的问题。
3. multi-polar [ 7mQlti5pEulE ] adj. 多极的 The world should be multi-polar. 世界应该多极化。
4. unilateral [ 5ju:ni'lAtErEl ] adj. 单边的 Any unilateral action will do the cause no good. 单边行为对这项事业没有好处。
5. bilateral [ bai5lAtErEl] adj. 双边的，双方的 The visit improved the bilateral relations greatly. 这次访问大大地改善了双边关系。
另类阅读：
The world will multiply its efforts to recover a multipolar world of. The USA would take unilateral actions, but it would hurt its bilateral relations with other countries. After all, the world needs multilateral cooperation.
轻松一刻：
When Martin got into the office, his colleagues were surprised to find both his ears were covered with bandage.
"What's wrong?" they asked.
"When I was watching the baseball match last night, my wife was ironing clothes beside me." Martin said, "the moment she left, the bell rang. I was watching the match as I picked up the iron and put it on my ear, so..."
"How comes the other ear was hurt?"
"You will never expect it. The moment I hung off, the guy called again."