单项选择题
A. real B. main C. only D. practical
In 1845 Sarah Mather invented a submarine telescope tha...
单项选择题In 1845 Sarah Mather invented a submarine telescope that could be used to locate and study underwater objects.()
A. illuminate B. raise C. find D. examine
The loss of her cat was the greatest grief the child ha...
单项选择题The loss of her cat was the greatest grief the child had known.()
A. trial B. tragedy C. misconduct D. sorrow
In order to improve our standard of living, we have to ...
单项选择题In order to improve our standard of living, we have to accelerate production().
A. speed up B. decrease C. stop D. control
