oy the scenery, Sara would spend longhours on the train ______ travel by air.

Whenever I go to Beijing, ____ is quite frequent, I will go to visit the Great Wall

n’t like coffee _____tea, but water．

Evidence has been piled up ______ drinking waterafter getting up in the morning contributes to one’s health.

People along the river didn’t allow them to ________ a factory so as not to pollute the water.