There’s no way of knowing why one man makes an important discovery ___ another man, also intelligent, fails.

 Then I usually lay there just              the ceiling, thinking about everything that could go wrong.

The problem is so complex that I'm afraid it will take me several hours to________．

The CCTV show Chinese Characters Dictation Competition has taken the country by storm, which is partly designed to arouse people’s ________ in Chinese. 

She intended to be a doctor, but a serious eye infection forced her to ____ the idea.