He never gave up, _____ he failed many times.[ ]
A. and
B. though
C. or
D. but
答案:B
氖光
阴阳异常消长主要表现为
A.阴消阳长、阳消阴长B.阴阳偏盛、阴阳偏衰C.由阴转阳、由阳转阴D.阴损及阳、阳损及阴E.阴盛格阳、阳盛格阴