BPSK下扩频因子是8,保证传输不变的情况下改用QPSK,则扩频因子应该为:()
A.2
B.4
C.8
D.16
参考答案:D
根据情景和所给的首字母,在空格内填入一个适当的单词,使对话意思完整
What must you do when you get a present for your birthday? You have to sit down and
w 1 a thank-note. The w 2 “thank you” are very important. We have to use them very often. We say them when someone gives us a drink, h 3 us to pick up things, or lends us a book.
A 4 important word is “please”. Many people forget to use it. It is n 5 polite to ask someone to do something without s 6 “please”. We have to use it when we ask for something, too. It may be a book or a pencil, more rice or help.
We have to l 7 to say “sorry”, too. When we hurt someone, we’ll have to go up to say “we’re sorry”. When we forget something, we will a 8 say “sorry”.
These three words are easy b 9 important. Our children must learn to use them. They are pleasant words to use in a 10 language.
近年来,森林野生植物资源获得较大规模的开发利用,如竹柏、黑沙草、油瓜、文冠果、蝴蝶果、峡木、破布木、五角木槭、水冬瓜等,请判别这些植物开发利用中属下列哪一种()
A、天然饮料
B、新油源植物