American researchers have developed a technique that may become an important tool in fighting AIDS virus from attacking its target-cells in the body's defense system．When AIDS virus enters the blood，it searches for blood cells called T4 lymphocytes(淋巴细胞)．The virus connects to the outside of T4 lymphocytes．Then it forces its way inside．There it directs the cells' genetic material to produce copies of the AIDS virus．This is how AIDS spreads．
Researchers think they may be able to stop AIDS from connecting to T4 ceils．When AIDS virus finds a T4 cell，it actually connects to a part of the cell called CD4 protein．
Researchers want to fool the virus by putting copies or clones of the CD4 protein into the blood．This way the AIDS virus will connect to cloned protein instead of the real ones．Scientists use genetic engineering methods to make the clones．Normally a CD4 protein remains on the T4 cell at all times；the AIDS virus must go to it．
In a new technique，however，the cloned CD4 protein is not connected to a cell．It floats freely，so a lot more can be put into the blood to keep the AIDS virus away from real CD4 protein on T4 cells．One report says the．AIDS virus connects to cloned protein just as effectively as it connects to real protein．That report was based on tests with blood cells grown in labs．The technique is just now beginning to be tested in animals．If successful，it may be tested in humans within a year．
The new technique can     .

A．cure AIDS

B．kill the AIDS virus

C．prevent the AIDS virus from spreading

D．produce new anti-AIDS cells

When the AIDS virus enters the blood，it is reproduced by     .

A．itself

B．the blood cells

C．the CD4 protein

D．the genetic material of T4 lymphocytes

The AIDS virus connects to cloned protein instead of the real CD4 protein because    .

A．cloned protein stays On the T4 cells

B．it connects to cloned protein more effectively

C．cloned protein is made by genetic engineering methods

D．cloned protein floats freely，and many more can be put into the blood

Which of the following statements is NOT true?

A．The new technique has been tested in labs．

B．The new technique is being tested in animals．

C．The new technique may be tested in humans．

D．The new technique is now under clinic test．

The best title for this passage is     ．

A．AIDS-a deadly disease

B．A new technique in fighting AIDS

C．The spread of AIDS virus

D．The cloned CD4 protein