Which of the following findings would indicate that the goals for total parenteral nutrition (TPN) are being achieved for the client

A. Serum glucose level of 96.
B. Weight gain of 0.5 pounds/day.
C. Urine negative for glucose.
D. Serum potassium level of 4 mEq/L.

如图1所示电路中，R是一个定值电阻，R_l是一个半导体材料制成的热敏电阻，其阻值随温度变化的曲线如图2所示，当开关闭合且电阻R_t所处的环境温度升高时，电流表示数______，电压表示数______．（填“增大”、“减小”或“不变”）