99-10-13 普1-10 [求助][讨论]please help me to work out these problems

  ure iron cannot be hardened by heating and cooling , as------, because iron lacks the necessary carbon.

   A steel it can   B can steel   C  with steel can    D so can steel

   Is "as" be a subject???

The  computer has dramatically affected ---photographic lenses are constructed .

A  is the way   B that the way   C which way to   D the way

这里是不是省略了THAT

as
1
used in comparisons
as ... as
They want peace as much as we do. Helen comes to visit me as often as she can. I can't run as fast as I used to.
2
in the way that someone says or that something happens, or in the condition something is in
Do as I say! We'd better leave things as they are until the police arrive. The money was repaid, as promised. He did not need to keep moving house, as his father had. Roberta was late as usual (=in the way that she usually was) .
3
used to say that what you are saying is already known or has been stated before
David, as you know, has not been well lately. As I explained on the phone, your request will be considered at the next meeting. As Napoleon once said, attack is the best method of defence.
4
while or when
I saw Peter as I was getting off the bus. As time passed, things seemed to get worse. Just as the two men were leaving, a message arrived.
5
used to state why a particular situation exists or why someone does something
As it was getting late, I turned around to start for home. We asked Philip to come with us, as he knew the road.
6
though
Unlikely as it might seem, I'm tired too. Try as she might, Sue couldn't get the door open. As popular as he is, the President hasn't always managed to have his own way.
7
as for somebody/something
used when you are starting to talk about someone or something new that is connected with what you were talking about before
Kitty's got so thin. And as for Carl, he always seems to be ill. You can ask the others, but as for myself, I'll be busy in the office.
8
as yet [used in negatives] until and including the present time - used to say that something has not happened although it may happen in the future
We've had no word from Colin as yet.
9
as if.../as though...
a) in a way that makes it seem that something is true or that something is happening
It sounds as though she's been really ill. Gary was behaving as though nothing had happened. Mrs Crump looked as if she was going to explode. Beckworth shook his head as if to say 'Don't trust her'.
b) used to emphasize that something is not true or will not happen
She said she'd never speak to me again. As if I cared (=I do not care at all) .'Don't try any funny business, now.' 'As if I would.' As if! spoken informal He asked if I'd go out with him. As if! (=it is extremely unlikely that I would go out with him)
see usage note as1
10
it's not as if
used to say that something cannot be the explanation for a situation or someone's behaviour because it is not true
Why do they never go on holiday? I mean it's not as if they're poor is it? I don't know why you're so frightened of her, it's not as if she's got any power over you.
11
as it is
a) because of the situation that actually exists - used when that situation is different from what you expected or need
They hoped to finish the kitchen by Friday, but as it is they'll probably have to come back next week.
b) already
Just keep quiet - you're in enough trouble as it is.
12
as from/of something
starting from a particular time or date and continuing
As from today, you are in charge of the office. As of now, there will be no more paid overtime.
13
as against something
in comparison with something
Profits this year are $2.5 million as against $4 million last year.
14
as to something
a) concerning
Frank was very uncertain as to whether it was the right job for him. advice as to which suppliers to approach He kept his rivals guessing as to his real intentions.
b) formal used when you are starting to talk about something new that is connected with what you were talking about before
As to our future plans, I think I need only say that the company intends to expand at a steady rate.
15
as it were
used when describing someone or something in a way that is not quite exact
Jim Radcliffe became our idol, as it were, the man we all wanted to be.
16
as is/was/does etc
formal used to add that what you have said is also true of someone or something else
Eve's very tall, as was her mother. I voted Labour, as did my wife.

Thank u very much!!