I _____ in Guilin for several years.[ ]
A. lives
B. lived
C. has lived
D. have lived
答案:D
耐火混凝土分层浇灌,每层浇灌厚度取决于耐火混凝土的()和捣固方法。
A、粘度
B、密度
C、稠度
D、硬度
塌房