"小儿虽无病,早起常膏摩囟上手足心,甚辟风寒"见于()
A.宋太医院《圣济总录》
B.葛洪《肘后救卒方》
C.四明陈氏《小儿按摩经》
D.孙思邈《千金方》
参考答案:D
发光二极管和光电二极管正常工作时,应外加()
A.均加正向电压
B.均加反向电压
C.前者加反向电压,后者加正向电压
D.前者加正向电压,后者加反向电压
Physics ________ my favorite subject. I like it so much that I wish we had a physics class every day.
A.is
B.are
C.was
D.have been