15578456348119

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

ROBOTS

Ever since it was first possible to make a real robot, people have been hoping for the invention of a machine (15) _______ would do all the necessary jobs around the house. If boring and repetitive factory work could be (16) _______ by robots, why not boring and repetitive household chores too?

For a long time the only people who really gave the problem their attention were amateur inventors. And they came up against a major difficulty. That is, housework is actually very complex. It has never been one job, it has always been many. A factory robot (17) _______ one task endlessly until it is reprogrammed to do something else. It doesn’t run the whole factory. A housework robot, on the other hand, has to do several different types of cleaning and carrying jobs and also has to cope (18) _______ all the different shapes and positions of rooms, furniture, ornaments, cats and dogs. (19) _______, there have been some developments recently. Sensors are available to help the robot locate objects and avoid obstacles. We have the technology to produce the hardware. All that is missing the software- the programs that will operate the machine.
Điền vào ô 17.

A. carries over

B. carries out

C. carries off

D. carries away

Một điện trở R₁ được mắc vào hai cực của một nguồn điện có điện trở trong r = 4W thì dòng điện chạy trong mạch có cường độ I₁=1,2A. Nếu mắc thêm một điện trở R₂ = 2W nối tiếp với điện trở R₁ thì dòng điện chạy trong mạch có cường độ I₂=1A. Giá trị của điện trở R₁ bằng

A. 5W    

B. 6W 

C. 7W  

D. 8W