Most of unstressed vowels of function words (words such as the, to, on, can, and so on) are reduced to the schwa /ə/.
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Native speakers of English often use schwa vowels in stressed syllables.
A. 对
B. 错
What’s the difference of pronouncing between /3:/ and /ə/?/ə/ is made similarly to /3:/, but with less tension.
A. 对
B. 错
一般用于受力不大且不常拆卸的场合的连接方法是()
A. 螺栓连接
B. 双头螺柱连接
C. 螺钉连接
螺栓连接画法中，下列说法错误的是（）。
A. 板上的孔直径大于螺纹大径
B. 螺母上有倒角
C. 螺栓是不剖的
D. 上下板的剖面线方向是平行
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