The professor worked for 7 hours at a ________.
A
此题考查的是固定词组搭配。atastretch一口气地。
During the past two decades, research has ________ our knowledge of daydreaming.
It has been found that a strong ________ help overcome the effects of distraction.
The outline of rooftops and chimneys ________ against the pale sky.
Although Tom is satisfied with his academic achievement，he wonders _______ will happen to his family life .