1. In 1642, Pascal designed an adding machine, which ___ help in the computation of taxes.
A. was to C. have to
B. were able to D. was allowed to
2. I will record the film and we ___ to watch it later.
A. can C. will be able
B. is to D. were to
3. The CPU determines which operations ___ be carried out and in what order.
A. may C. are allowed to
B. are to D. has to
4. Only a few people ___ to see these files.
A. has C. are allowed
B. may D. will be able to
5. After you write your program, you ___ to test it and debug it to remove all the mistakes.
A. must C. will have
B. is able D. are allowed
6. In 1995, Philips and Sony introduced a digital videodisc (DVD), which ___ store up to 4.7 gigabytes of data.
A. are allowed to C. must
B. were to D. was able to
7. A DVD has the same dimensions as a standard CD but cannot be read by a standard CD player, although a DVD player ___ read standard CDs.
A. have to C. is able to
B. were able to D. will have to
8. Text and pictures ___ be scanned into the computer by means of this device.
A. can C. has to
B. will be able D. was allowed to
9. The ENIAC computer ___ to be rewired manually for each new task.
A. had C. were
B. must D. are
10. Information for a digital computer ___ be in the form of digits or numbers.
A. has to C. will be able to
B. may D. is to
11. Only the company’s executives ___ to use the corporate database.
A. may C. are able
B. has to D. must
12. Our lab assistant ___ repair this electronic device tomorrow.
A. were to C. is allowed to
B. will be able to D. have to