重点讲解：
1. be studded with
布满…的；有很多…的；
eg. The sky was studded with twinkling stars.
天空满布着闪烁的星星。
eg. The business history of the past two decades is studded with failed mega-mergers.
在过去20年的商业史上,失败的“巨无霸”合并案比比皆是。
2. be low in
成分少的；含量低的；
eg. They look for foods that are low in calories.
他们要找低卡路里的食物。
eg. They are weakened by a diet that is low in protein.
他们日常饮食中蛋白质含量不足，因而身体虚弱。
3. be poor in
贫乏的；缺少的；
eg. He is poor in money, but rich in knowledge.
他贫于金钱，但富于学问。
eg. It has come to my notice that he was poor in health.
我注意到他身体不好。
4. if not for
（用于条件句中）如果不是为了，要不是；
eg. If not for John, Brian wouldn't have learned the truth.
要不是因为约翰，布赖恩也不可能知道真相。
eg. The earth would be a frozen ball if it were not for the radiant heat of the sun.
如果没有太阳辐射的热量，地球就会变成一个冰球。
5. in abundance
大量；丰富；充足；
eg. Food was in abundance.
食品充足。
eg. But the report has evidence in abundance.
但是报告显示的证据十分充足。