【单选题】(76-78页Unit 3) Which of the following advantages of the internet is not mentioned in Paragraph 1?
D.
Communicating with friends.
【简答题】有一直流负载,需要直流电压UL=36v,电阻RL=10欧,若采用桥式整流电路如图所示,求电源变压器二次电压U2 电流IL以及二极管电流Iv
【简答题】列竖式计算 87÷3= 76÷4= 49÷3=验算.
【单选题】2 (76-78页Unit 3) Cars are mentioned in Paragraph 2 to show____
A.
the Internet can provide maps to guide drivers in traffic jams
B.
people can solve air pollution and traffic jams by using the Internet
C.
the Internet, like cars, brings convenience and causes problems at the same time
D.
the negative effects they cause