[判断题]收缩率比是指龄期28d掺外加剂混凝土与基准混凝土干缩率的比值。
A.正确
B.错误

There are countless parents who will not allow their children to play violent video games, in which players are able to kill, maim, dismember or sexually assault human images in depraved ways. The video game industry rates them, and some stores use that rating to decide whether to sell a particular game to a minor.
But California went too far in 2005 when it made it illegal to sell violent video games to minors. Retailers challenged the law, and a federal appeals court rightly ruled that it violates the First Amendment. Last week, the Supreme Court said that it would review that decision. We hope it agrees that the law is unconstitutional. California’s law imposes fines of up to $1,000 on retailers that sell violent video games to anyone under 18. To qualify, a game must, as a whole, lack serious literary, artistic, political or scientific value for minors.
But video games are a form of free expression. Many have elaborate plots and characters, often drawn f
A. It treated video games as literature and art
B. It opposes the political and scientific value of video games
C. It places too little trust in voluntary rating
D. It attempts to restrict the content of the games