L-9：let someone down 使某人失望

A:That's really a let-down.

A：那可真令人失望。

B:Yeah. He really does let me down.

B：是的，他确实让我失望。

A:But that should not be the reason for you to lose heart.

A:但这不应该成为你灰心的理由。

B:I'm at the end of the tether. I run out of ideas.

B：我再没有精力了，我已无计可施了。