题目

已知sin(3π+α)=lg，则tan(π+α)的值为（    ）A．-    B．C．±    D． 答案：C解析：由题设sin=∴cos=±=±,∴tan()=tan=±15. ―Thomas_great interest in learning when he wasvery young.―Yes. He knew how to _ new words in thedictionary at the age of 6.A.showed ；look up B.showed ；look forC.gave ； look at D.gave;look out