answers plz

[premkumar]

In bas-relief sculpture, a design projects very slightly from its background, _________ some coins.
1.as on
2.because
3.the way that
4.similarly

With age, the mineral content of human bones, decreases, ____________ them more fragile.
1.make
2.and to make
3.thereby making
4.which it makes.

the first explorer _______ california by land was jededian strong smith, a trapper who crossed the southewestern deserts of the united stated in 1826
1.that he reached
2.reached
3.to reach
4.reaching it

________many copper mines in the state of Arizone, a fact which contributes significantly to the states economy
1.there are
2.they are
3.of the
4.the

[Codename Gordon]

First sentence: 1.
Second sentence: 3.
Third sentence: 3.
Fourth snetence: 1.

[een]

Hello, premkumar!!!
To my mind,
First sentence: 1.

Second sentence: 3.
IMHO
Third sentence: 2 (reached).

Fourth snetence: 1.

All the best!
een

[alex_cute]

guys, my answers: 4, 3, 3, 1.

4 for the first one because in order to put AS ON you need some verb there. For example, AS ON would be correct if you had AS IT DOES ON some coins.

in the third one, you can't say REACH because you will loose the meaning of the sentence - try to read it with REACH in.