A lot of people could fall ill after drinking contaminated water.

单项选择题In 1845 Sarah Mather invented a submarine telescope that could be used to locate and study underwater objects.

单项选择题Patricia stared at the other girls with resentment．

单项选择题Mary is looking for the book she lost yesterday.()

A. trying to find
B. trying to read
C. trying to buy
D. trying to borrow

单项选择题Sometimes it is advisable to book hotels in advance.()

A. possible
B. profitable
C. easy
D. wise

单项选择题The kind of thing that happened last Saturday night is a regular occurrence in the village.()

A. event
B. presence
C. development
D. endeavour