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【单选题】
下列关于振子天线的说法正确的是【】A.
理想单极天线和自由空间相对应的天线相比，前者的辐射电阻为后者的 2 倍。
B.
理想单极天线和自由空间相对应的天线相比，前者的方向性系数为后者大的 4 倍。
C.
理想地面上方的对称振子与自由空间中相比，方向性系数前者最大可达到后者的 4 倍。
D.
半波折合振子和相同长度的半波振子相比，前者的方向性系数可达后者的 2 倍。
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【单选题】某交易者2020年2月 24日以26,550元/吨卖出沪铜 905合约 10手,第二天以26000元/吨平仓,该交易者属于( )。
A.
长线交易者
B.
短线交易者
C.
当日交易者
D.
抢帽子者
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A.
few
B.
little
C.
fewer
D.
less
【单选题】Which of the following is NOT the reason why we teach pronunciation?
A.
To improve intelligibility in communication is one major reason for teaching pronunciation.
B.
Teaching pronunciation can also help students in other aspects of English learning.
C.
Pronunciation is the most important part in any language learning process.
D.
Good pronunciation is always important for students to achieve effective communication.
【判断题】There are no principles or rules for the pronunciation of English words.()
A.
正确
B.
错误
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【多选题】What are the principles for teaching pronunciation?
A.
Teaching pronunciation through student imitating
B.
Teaching pronunciation in the stream of speech
C.
Teaching pronunciation in context
D.
Teaching pronunciation through student modeling
E.
Teaching pronunciation through teacher modeling
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