risk of doing
one chance in a million 固定搭配

possibility/likelihood 只能接of/that，表示可能性，控制力弱，不能接to do
opportunity/chance 可以接of/that也可以接to do，区别在于：如果指机会大小等数学量的表达，只能接of，如：have a 70% chance of doing sth, 不能说have a 70% chance to do sth；如果强调有机会去开始某事，可以用 the opportunity/chance to do sth;
risk of doing sth；risk表示风险，对动作的发生与否控制力弱，不接to do；risk to sth/sb，对某事的风险；有引发癌症的风险，这个引发不单是指将来引发，它可以是过去引发、现在引发、将来引发，这些都是风险，所以更接近一种惯常的状态，不用 will

as little risk as one chance / a risk as little as one chance都可以
数字后面都加of，选b

BD差异：
a risk of sth/doing……的风险，a risk to sb/sth对……是个风险，a risk that……，风险的内容是……，没有a risk for doing和a risk to do
one chance in a million 是固定搭配，表示几率很小

1、risk 做cause的主语，所以排除risk to cause&risk for causing 的选项ADE
2、in the case of mathematical probabilities, you can only use 'chance of'.
3、it无法指代substances
4、With MOST adjectives, it's ok to write "NOUN as ADJ as..."
E.g., Women as beautiful as my wife are rare.
On the other hand, if the adjective is "many", "few", "much", or "little", then you cannot write "NOUN as ADJ as..."
Instead, you must write
as many NOUNs as...
as few NOUNs as...
as much NOUN as...
as little NOUN as...

risk of causing cancer NOT risk for causing cancer

one chance in a million 是固定搭配，表示几率很小
B选项是 risk of sth/doing sth 做什么的风险
A选项是 risk to sb/sth 对什么来说是风险
但没有 risk to do sth 或者 risk for doing sth的表达

the same reasoning applies here; you're looking for idiomatic usage that agrees with 'risk', not 'chance'.
the last poster is correct in one sense, which is that there are correct idiomatic usages of 'chance to'.

as small a collection as three pirated albums has occasionally drawn the attention of the recording industry.
in this case, 'collection', not 'albums', is the subject of 'has drawn' (which can be inferred from the fact that 'has' is singular).
this is the case because this sentence is equivalent to the following rearranged version:
a collection as small as three pirated albums has occasionally drawn the attention of the recording industry.

1. risk of doing sth., risk doing sth. 是固定搭配，由此排除A/D；
2. one chance in a million 是固定搭配，表示几率很小。由于修饰risk时，as little risk as one chance in a million 和 a risk as little as one chance in a million都是正确的表达方式。由此排除A；
3.D if the adjective is "many", "few", "much", or "little", then you cannot write "NOUN as adj. as..." Instead, you must write as many NOUNs as、as few NOUNs as、as much NOUN as、 as little NOUN as…

one chance in a million
chances of doing sth.

a risk of doing/sth

toxic substances present risk to cause cancer.VS toxic substances present risk of causing cancer
不定式和ing的区别：不定式表示引起状态的改变，ing表示状态的稳定，没有发生改变。
(1) 不定式出现在主语，表示说话者能影响状态的改变，如：to prepare GMAT takes a long time.表示事说话者个人准备GMAT花了很长时间。
(2)不定式作宾语或宾补，表示谓语动词能引起状态的改变，如: We ask hime to leave. ask要求，要求能使他离开这件事发生。He is believed to be a good man. 因为相信，所以他才是个好人。
(3)不定式作状语或定语，表示主句的发生能引起状态的改变，如：To see you, I went to New York.
本题cause cancer做宾补，是否用不定式看谓语动词present的影响力。
risk of doing sth，作某事的风险

1、present as little risk as one chance in a million 和present a risk as little as one chance in a million都是正确的表达方式
2、a risk of sth/doing……的风险，a risk to sb/sth对……是个风险，a risk that……，风险的内容是……，没有a risk for doing和a risk to do
E，it只能指代单数名词risk，present a risk for the risk to cause cancer，错

1、present as little risk as one chance in a million 和present a risk as little as one chance in a million都是正确的表达方式
2、a risk of sth/doing……的风险，a risk to sb/sth对……是个风险，a risk that……，风险的内容是……，没有a risk for doing和a risk to do
E，it只能指代单数名词risk，present a risk for the risk to cause cancer，错！

1. risk of doing sth., risk doing sth. 是固定搭配，由此排除A/D；
2. one chance in a million 是固定搭配，表示几率很小。由于修饰risk时，as little risk as one chance in a million 和 a risk as little as one chance in a million都是正确的表达方式。由此排除A；
3. C：that后面it引导的是定语从句，修饰的对象是risk。而从逻辑意义上看risk不应该cause cancer。排除C；
4. E：a million for it to cause 表达错误。排除E。
5. as many NOUNs as...
as few NOUNs as...
as much NOUN as...
as little NOUN as...

You're looking for idiomatic usage that agrees with 'risk', not 'chance'.
例句as small a collection as three pirated albums has occasionally drawn the attention of the recording industry.
in this case, 'collection', not 'albums', is the subject of 'has drawn' (which can be inferred from the fact that 'has' is singular).

With MOST adjectives, it's ok to write "NOUN as ADJ as..."
E.g., Women as beautiful as my wife are rare.

On the other hand, if the adjective is "many", "few", "much", or "little", then you cannot write "NOUN as ADJ as..."
Instead, you must write
as many NOUNs as...
as few NOUNs as...
as much NOUN as...
as little NOUN as...

老师，这个题目如何分析？能否讲解一下？

mark, D&E
D if the adjective is "many", "few", "much", or "little", then you cannot write "NOUN as adj. as..." Instead, you must write as many NOUNs as、as few NOUNs as、as much NOUN as、 as little NOUN as…
E的问题是同D