(A) 条件(1)充分，但条件(2)不充分． (B) 条件(2)充分，但条件(1)
题型：问答题
问题：
(A) 条件(1)充分，但条件(2)不充分．
(B) 条件(2)充分，但条件(1)不充分．
(C) 条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
(D) 条件(1)充分，条件(2)也充分．
(E) 条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．
During a five-day period, Monday through Friday, the average (arithmetic mean) high temperature was 86 degrees Fahrenheit. What was the high temperature on Friday
(1) The average high temperature for Monday through Thursday was 87 degrees Fahrenheit.
(2) The high temperature on Friday reduced the average high temperature for the week by 1 degree Fahrenheit.