岸台采用NBDP系统播发气象信息,应采用()模式。
A、ARQ
B、SFEC
C、CFEC
D、TDMA
参考答案:C
用所给单词的正确形式填空。
1. I'm ___________ (big) than you.
2. You're taller than ___________ (I).
3. Lin Jun is ___________ (short) than Mike.
4. Sarah is ___________ (swim) in the river.
5. Amy usually ___________ (go) to school on foot.
6. Do you like ___________ (pear)?
7. I can ___________ (make) a kite.
8. What ___________ (do) she do on the weekend?
2009年初,河南、山东等省大旱,政府采取飞机撒播和高炮火箭发射干冰、碘化银(AgI)等增雨剂实施人工降雨,以缓解旱情.下列有关增雨剂的说法错误的是( )
A.干冰不是冰,而是固态二氧化碳
B.干冰还可为春节联欢晚会营造云雾仙境
C.碘化银中碘元素的化合价是+1
D.AgI中碘与银的元素质量比是127:108