A． a train or a plane
B． a boat or a train
C．a car or a boat ．
D．a plane or a car
[单选题]29． The writer thinks that people in large cities should __________ ．A． stop the used water from getting into undergroundB． only use the water from the riversC． make their used water clean againD． use as much sea water as possible
[单选题]29． Why do people like teleshopping?A． Because they like watching TV．B． Because they can do some shopping at home，C． Because they like the heavy traffic．D． Because they think the things on TV are good．
[单选题]29． When it thunders, we always see the light before we hear the sound．______ It’s becauseA． our eyes are in front of our earsB． our eyes are cleverer than our earsC． our eyes can see but our ears can-tD．light goes faster than sound
50.When you exchange business cards with other people,present and receive with b
[单选题] When a large packet wants to travel through a network whose MTU is too small, one solution is to allow routers to break up the packet into （）. （）A. messages B. frames C. fragments D. bits
[单选题]All the traveling_____are paid by the company if you travel on business.A.c
What are the things that people usually do before travel?A. Book train or flight