In organic chemistry, the concept of cis-trans isomers is important.

In organic chemistry, cis-trans isomerism is an important concept.

The rotator cervicis is an important muscle for turning the neck left and right.

Please tell me the way to solve this problem.

We are considering introducing a new voting system.

The police used a water cannon against the demonstrators.

Learning a new input method is difficult.

The sending of the email has been completed.

I sent you an email.

His solemn attitude moved everyone.