VOA慢速英语:Breastfeeding, a Skill That Mom and Baby 'Learn From Each Other'

grow out of产生自…, 从…发展

例句：The book grew out of a series of lectures.
      这册书是由一系列讲义汇集而成的。

      Her sympathy grew out of understanding.
      她的同情是由于理解产生的。

2.In fact, she could be feeding her son right now.

could表示猜测

can用来表示"可能"的猜测

can可用来表示"理论上的可能性"，用来表示事件或情况在理论上可能发生，并不牵涉到是否真的会发生。在这种用法中can只能与动词原形连用。

can可用来表示现实的可能性，但只能用在疑问句之中，可与动词原形或不定式的完成式连用。

Who can that be at the door?（门外会是谁？）

Can it be Susan?（她会上哪儿去了呢？）

can't和couldn't表示"不可能"的猜测，在这种用法中can't和couldn't用法相同，只是couldn't的语气更弱。下面以can't为例：

对现在存在的状态的"不可能"的猜测：

It can't be true.（这不可能是真的。）

He can't be Mike's father.（他不可能是迈克的爸爸。）

She can't be more than thirty.（她不可能超过三十岁。）

对正在发生的动作或行为的"不可能"的猜测：（can't + be + 动词的现在分词）

He can't be watching TV at home.I met him at school a moment ago.（他不可能在家看电视，我刚在学校见过他。）

He can't be sleeping in his bedroom.I saw him go out.（他不可能在卧室睡觉，我看见
他出去了。）

对过去的动作或行为的"不可能"的猜测：（can't + have + 动词过去分词）

She can't have gone to school.It is Saturday.（她不可能上学去了，今天是星期六。）
 
They can't have gone out because the light is on.（他们不可能已经出去了，因为灯还开着。）

3.So basically, if we were to place a baby on the mother's abdomen, the baby would actually crawl up the mother's chest and choose which breast it would like to latch on to.

latch on抓住,占有,理解

例句：I latched on to their conversation.
      我仔细倾听他们的谈话。

4.If children were exclusively breastfed for six months, continued to breastfeed up to two years, with appropriate additional food from six months onwards, we could save 1.5 million children under five years of age out the 8.8 million that we estimate to die currently every year.

If引导条件句，只是这个条件比较长。we could save表示虚拟语气，在前面的条件满足的条件下可以产生的结果。