相对增益为15dBd天线,其绝对增益为()dBi。
A.15
B.17
C.15.15
D.17.15
参考答案:D
不是起自总腱环的是()。
A.下直肌
B.下斜肌
C.上斜肌
D.内直肌
E.上直肌
__________ there a map and two posters on the wall?[ ]
A. Have
B. Has
C. Is
D. Are