Choose the word that is closest in meaning to the underlined word. When you think of “scientific breakthroughs,” you probably think of the major, history-shifting ones. Newton’s laws of gravity! Einstein’s theory of relativity! Penicillin!

If I had closed the window, the cat _____________ out.

London’s nothing like it ________!

With reference _____ your order, I confirm that we have sent the goods to you. 

Choose the word that is closest in meaning to the underlined word. 3D printing continues to hold great promise for a wide range of industries, but due to cost and its still limited functionality, it remains greater in theory than in practice.

I don’t know who _______ yesterday.

Where _____ between 2005 and 2007?

By the end of the week I _______ here for four months.

Life is hard for ________.

Choose the word that is closest in meaning to the underlined word. Though we’ve been able to confirm the existence of black holes by measuring motions of individual stars orbiting them, actually getting images of these light-eliminating things has proven more difficult.