C is sometimes referred to as a ’high -level (66) language’. Some people think that’s an insult, but it’s actually a deliberate and significant aspect of the language. If you have (67) in assembly language, youll probably find C very natural and comfortable (although if you continue to focus too heavily on machine - level details, youll probably end up with unnecessarily non- portable programs). If you havent programmed in assembly language, you may be frustrated by C ’s lack of certain higher - level features. In either case, you should understand why C was de- signed this way: so that seemingly - simple constructions expressed in C would not expand to arbitrarily expensive ( in time or (68) ) machine language constructions when (69) . If you write a C program simply and succinctly, it is likely to result in a succinct, efficient machine language executable. If you find that the (70) resulting from a C program is not efficient, it’s probably because of something silly you did, not because of something the compiler did behind your back which you have no control over. In any case, there’s no point in complaining about C’s low - level flavor: C is what it is.

A. site B. place C. space D. dimension

在HTML语言中，（）可用来为图像定义一串预备的可替换的文本。

A.alt

B.Replace

C.text

D.Title