21.   Q. Do underground nuclear tests create caverns?

22.   Ray E. Kidder, a Livermore physicist who helped pioneer hydrogen bombs, said small-scale thermonuclear research was attractive to weapon scientists in the absence of underground test explosions.

23.   She and other critics say that countries would have trouble distinguishing between subcritical nuclear tests and illegal underground tests of small nuclear weapons.

24.   Speaking eight months before India stunned the world in May with its five underground nuclear tests, Gujral had a word of advice for Clinton.

25.   The blast is also expected to scientists identify and measure secret underground nuclear tests conducted by India, Pakistan, China or by rogue states.

26.   The Clinton administration defined a comprehensive test ban as permitting only extremely low-yield underground tests.

27.   The current and four former chairmen of the Joint Chiefs of Staff support the test ban, which would prohibit underground nuclear tests.

28.   The meeting of the two leaders, probably in a month, would be their third since India and Pakistan conducted underground nuclear tests in May.

29.   The ousted government shocked the world last May by conducting underground nuclear tests, which were then matched by Pakistan.

30.   The plan is not considered ridiculous by scientists, but nobody has accepted it as a rationale for underground nuclear tests.