The argument presented in the paper is valid.

I need to replace the ink cartridge in my printer.

She spoke with a clear intonation.

The executives gathered in the boardroom to discuss the company's future plans.

I need help with the usage of this software.

The security system will alert the staff if it detects smoke.

He is a dependable friend who I can always rely on.

Identification is required to enter the building.

Please send me the invoice including the price and shipping fee.

Before we get into the details, let me give you a brief overview of the project.