司马光利用什么东西来提醒自己努力读书?[ ]
A.尖锥
B.闹钟
C.警枕
答案:C
The doctor Robert carefully as soon as he was taken to the hospital.[ ]
A. look at
B. looked over
C. look after
D. looked for
蜡制成蜡型后应冷却固定,主要是为了防止
A.应力松弛变形
B.冷却收缩变形
C.蠕变变形
D.弹性形变变形
E.聚合收缩变形