The quality of the phone signals has been improved through ___ developments in digital technologies.
Đáp án B: Present Perfect
Stephanie: "Oh, no! I left my book at home. Can I share yours?" Scott: "______ "
As a millionaire who liked to show off her wealth, Mrs. Smith paid______________________________________________ we asked.
Supporters of free-market globalization point out that_____________________ .
She asked me______I was looking at.
The packages___________________ so that it would be easier to carry them.
The Lake District,____________________ was made a national park in 1951, attracts a large number of tourists every year.
_______ has been a topic of continual geological research.
Only one of our gifted students______to participate in the final competition.
He_______________us but he was short of money at the time.
In spite of her abilities, Laura has been_____________________ overlooked for promotion.