Over the last three years a scientist had an average (arithmetic mean) yearly in come of $45,000. The scientist earned 1 times as much the second year as the first year and times as much the third year as the first year. What was the scientist’s income the second year ？（）

单项选择题During the four years that Mrs. Lopez owned her car, she found that her total car expenses were $18,000. Fuel and maintenance costs accounted for of the total and depreciation accounted for of the remainder. The cost of insurance was 3 times the cost of financing, and together these two costs accounted for of the total. If the only other expenses were taxes and license fees, then the cost of financing was how much more or less than the cost of taxes and license fees ？（）

A.$1，500more
B.$1，200more
C.$100less
D.$300less
E.$1，500less

单项选择题Larry saves x dollars per month. Will Larry’s total savings one year from now exceed his present savings by at least $500 (Assume that there is no interest.)（） (1)In 6 months Larry’s total savings will be $900. (2)In 3 months Larry’s total savings will exceed his present savings by $150.

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.