To make black boxes easier(for us) to discover under water, they can let out signals for 30 days.
参考译文:为了使/让我们更容易在水下发现黑匣子,它们可以发出30天的信号。
解答:以上to make black boxes easier for us to discover under water,为不定式短语作目的状语,不定式前面省略了“逻辑主语for us”所以只能用不定式主动结构“to discover under water”,black boxes是不定式“to discover under water”的逻辑宾语。
备注(1):名词短语“black boxes”是第1个不定式“to make”的宾语成分
备注(2):名词短语“black boxes”是第2个不定式“to discover under water”的逻辑宾语成分
备注(3):easier for us to discover under water是“形容词短语”作“black boxes”宾语补足语。
备注(4):宾语“blacks boxes”与宾补“easier(for us) to discover”属于逻辑上主系表关系,相当于语法上主系表结构“Black boxes are easier (for us) to discover”=To discover black boxes are easier for us.=It is easier for us to discover black boxes.
以上句子类似于:This question is easy (for me) to answer.=To answer this question is easy for me.
以上句子类似于:It can make this question easy (for me) to answer.
【1】make+名词(宾语)+形容词(宾补)
It can make this question easy to answer.
备注:以上是名词(this question)作宾语,形容词(easy)作宾补。
【2】make+代词it(形式宾语)+形容词(宾补)+to do sth
It can make it easy to answer this question.
备注:以上是it为形式宾语,真正宾语为不定式(to answer this question),形容词(easy)为宾补。
备注:当不定式作宾语,且不定式后面带有形容词作宾补的时,必须在动词后面加上“形式主语it”然后在把不定式放在句末,即必须使用结构为“make it +形容词+to do sth”=使“做某事怎么样”。