I can never remember how to use those two common words, “sell,” meaning to trade a product for money, or _____________________ meaning an event where products are traded for less money than usual.
A. sale.
B. “sale,”
C. “sale
D. “to sale,”
查看答案
In Edgar Allen Poe’s _______________________ Edgar Allen Poe describes a man with a guilty conscience.
A. short story, “The Tell-Tale Heart,”
B. short story The Tell-Tale Heart,
C. short story, The Tell-Tale Heart
D. short story. “the Tell-Tale Heart,”
低频信号可直接从天线有效地辐射。
A. 对
B. 错
高频电子技术所研究的高频工作频率范围是300kHz~3000MHz。
A. 对
B. 错
为了有效的发射电磁波,天线尺寸必须与辐射信号的波长相比拟。
A. 对
B. 错
微信支付 
支付宝支付