产自贝壳体内,由于内分沁作用而生成的矿物珠粒叫什么?
参考答案:
珍珠
在测定性实验中:
(1)如图所示,在圆圈中填上电流表或电压表的符号.只闭合开关S1,可以测量定值电阻的阻值;只闭合开关S3,可以测量小灯泡的功率.请分别设计测量定值电阻的阻值和测量小灯泡功率时的记录实验数据的表格.
(2)如图所示,只闭合开关S2和S4,电源电压保持3V不变,电流表的量程是0~0. 6A,电压表的量程是0~3V,则电路中允许的最大总功率是 W.
______the general state of his health,it may take him a while to recover from the operation. [ ]
A. Civen
B. To give
C. Giving
D. Having given