54.A computer can calculate _______. (A)with lightning speed (B)accurately (C)with a speed 500,000 times faster than a person (D)all above www.henanzsb.com

51.Why does the author regard the electronic computer as the marvel of the machine age? (A)Because electronic computers are rare. (B)Because people know little about electronic computers. (C)Because electronic computers can do much more kinds of work that human beings can't. (D)Because electronic computers have been widely suspected.