问题
选择题
Wind power is an ancient source of energy ______________we may return in the near future. [ ]
A. on which
B. by which
C. to which
D. from which
答案
答案：C
搜题请搜索小程序“爱下问搜题”
Wind power is an ancient source of energy ______________we may return in the near future. [ ]
A. on which
B. by which
C. to which
D. from which
答案：C
唇颊面龋洞，腐质黄软
。唇面牙颈部白垩色脱矿斑。患儿夜里吃2次母乳，不刷牙。诊断是（）