The natural beauty of Mount Tai _______millions of tourists from all over the world every year.

Old-fashioned phones matter when wireless networks _____ in disasters.

Rather than ________on a crowded bus, he always prefers _______a bicycle .

 I'm afraid physics is completely ________ me and I have to ask you for help.

(2013·南京二模)—What do you think of the news in today's newspaper?—We shouldn't ________ the trouble of helping others only because what we do may invite trouble.