_____ all the inventions have in common is ______ they have succeeded.
| A．What; what | B．That; what | C．What; that | D．That; that |
_____ of their bad habits, the boys switched from being dependent on their parents to _____ for others.
| A．Having rid; sacrificing | B．To rid; sacrifice |
| C．Rid; sacrificing | D．Having been rid; sacrifice |
Scientists ______ thousands of chemicals before they decided on the right one in the end.
| A．tried out | B．found out |
| C．worked out | D．turned out |
To some extent, uncontrolled information from the website that many people turn _______ false.
| A．to prove | B．to proves | C．prove | D．proves |
People who tend to focus on ______ while speaking a foreign language may find that they worry too much about making mistakes.
| A．fluency | B．agency | C．policy | D．accuracy |
Life is like _________ ocean; only ________ strong-willed can reach the other shore.
| A．an; a | B．an; the |
| C．the; the | D．the; a |