目前水火弯板和火工矫正中最常用的冷却方法是（）。
A、自然冷却
B、正面跟踪水法
C、背面跟踪水法
D、冷风冷却
参考答案：B
根据首字母或中文提示在答题卡上填写完整的单词
1. We were c______ about him when we heard of the accident.
2. They talked about it for hours. F_______, they decided not to go.
3. Here are Daphne and David; the _______ (后者) is my brother.
4. She's gardening _______ (在户外)now.
5. Steve p______ walking to driving,for he thinks it's a better way to exercise.
草木灰是将枯枝杂草等烧成的灰，含（）较多，属于碱性肥料。
A、氮
B、钾
C、磷
D、硫
