Question

such as后面的句子成分

请问下面的句子成分问题
What is more,salts such as perchlorates provide a way for Martian soils to take up water from the atmosphere.
such　as　后是定语还是同位语呢?for后面应该是宾补还是定语?
Perchlorate salts also appear to greatly extend the environmental conditions under which brines could remain liquid on Mars today.
appear　to　是作为情态动词什么的吗?好像是修饰extend的

Answer 1

很高兴为你解答.
1 such as,你可以把它理解成一个介词的作用,它后面常接接名词、动名词,起举例说明作用.
for 是表明一个对象,“ 对...而言”,后面的不定式才是后置定语.
2 appear 是不及物动词,它是做谓语,而不是修饰,extend 协助不定式构成appear to do 这个短语.
祝开心~!