If zt < -3, is z < 4 ?
(1) z < 9
(2) t < -4
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
当 z = 4 ~ 8 (不合)
条件二: t < -4
知 zt < -3 , 则当 t < -4 时 , z > 3/4 (不合)
条件一+二:9 > z > 3/4 (不合)
答案选E
条件二 当t=-5; z=10,tz=-50, 一样小于-3啊
联立也不可以, 当t=-5; z=8,tz=-40, 一样小于-3啊,所以都不可以证明z
1)设Z=-10000,不知道t:单独NS
2)Zt