题目内容：

    Scientists think that growing garden grass could be the secret to solving our energy needs, and we may soon be able to replace our gasoline with “grassoline”.

The team, including experts from Cardiff University in Wales, has shown that hydrogen can be taken from grass in useful amounts with the help of sunlight and a cheap catalyst(催化剂) —something that speeds up a chemical reaction without being used up.

It is the first time that this has been shown and it could lead to a sustainable(可持续的) way of making hydrogen, reported Asian News International. This could be an important kind of renewable energy because it is high in energy and it does not give out harmful gases when it is burned.

Study co-author Michael Bowker said, “This is really a green source of energy. Hydrogen is seen as an important future energy carrier as the world moves from fossil fuels to renewable energy, and our research has shown that even garden grass could be a good way of getting it.”

Cellulose(纤维素), which is a key part of plants and the biopolymer(生物聚合物) found in the largest numbers on the earth, could be a great source of hydrogen.

In its study, the team looked at the possibility of getting hydrogen from cellulose using sunlight and a simple catalyst.

This is called photocatalysis(光催化作用) and in it, the sunlight starts the catalyst, which then makes cellulose and water into hydrogen. The researchers studied the effectiveness of three metal-based catalysts, of which nickel(镍) especially interested the researchers, as it is a much more common metal than gold and palladium(钯) and it saves more money.

According to Bowker, producing hydrogen from cellulose using photocatalysis has not been studied in detail. The team’s research shows that large amounts of hydrogen can be produced using this method with the help of a bit of sunlight and a cheap catalyst.

The study shows that it is effective to use real grass taken from a garden. “This is important as it avoids the need to separate and clean up cellulose, which can be both difficult and costly,” said Bowker.

1.What are needed to get hydrogen from grass?

A. A catalyst and palladium. B. Water and cellulose.

C. Sunlight and a biopolymer. D. Sunlight and a catalyst.

2.Why is the new way of making hydrogen considered significant?

A. It is cheap, green and sustainable.

B. It is the best to produce the renewable energy.

C. It is more productive and efficient than other methods.

D. It can replace the way to make fossil fuels completely.

3.Why does nickel interest the researchers in making hydrogen from cellulose?

A. It can produce the largest amount of hydrogen.

B. It can avoid separating and cleaning up cellulose.

C. It is more common than other metals and costs less.

D. It works quicker than other metals during photocatalysis.

4.What does the author intend to tell us mainly in this passage?

A. Catalysts that could be taken from grass.

B. A new way of making hydrogen from cellulose.

C. The potential of hydrogen as a renewable energy.

D. The connection between hydrogen and photocatalysis.