电锯给人们的工作带来了方便，其核心部件是电动机，电动机的工作原理是_______
题型：填空题
问题：
电锯给人们的工作带来了方便，其核心部件是电动机，电动机的工作原理是_______ 。然而，电锯切割木料时锯齿与木料不断地撞击会发出恼人的噪声，当这种撞击的频率由快变慢时，声音的音调会逐渐变 (选填“高”或“低”)。怎样才能减小这种噪声的影响呢？请提出一种可行的法： 。
题型：填空题
语法填空
阅读下面短文, 按照句子结构的语法性和上下文连贯的要求, 在空格处填入一个适当的词或使用括号中词语的正确形式填空.
Traditional Chinese culture places much emphasis on food.Considered to be an important part of
each day, eating is far beyond simply (1)________ (meet) a need.However, people are living in a
fastpaced society now, so they hardly have time to enjoy their food.They need fast food.That is
(
2)________ China's fastfood market expands.
A foreign fastfood restaurant (3)________ (call) KFC arrived in China first, quickly followed by
(4)________ such as Pizza Hut and McDonald's.(5)________ the development of China, foreign
fastfood chains are realizing highspeed growth in China.However, these "junk foods" (6)________
(criticize) by health experts for long because they can't provide balanced nutrition.The experts also show
that some foreign fast food contains (7)________ food coloring, Sudan 1, (8)________ can cause
cancer.
In fact, China has many of its own traditional fastfood dishes.Among them, dumplings, soybean milk
and noodles are the most popular.(9)________ (compare) with foreign fast food, those traditional ones
are (10)________ (health). But many Chinese still enjoy the special taste and the good environment in
the foreign fastfood chains even though there exist some potential risks.