jaijune wrote:Hi All,
Please explain this sentence?
Which tense it is?
What is subject,verb,object?
The risks posed by a changing climate require action

Thanks in advance.

Here are the answers for your questions:
1. Present indefinite tense.
2. Subject: The Risks
3. Verb: Require
4. Object: Action
How do you find the subject of this sentence?
Think "NOUN+Modifier" becomes subject of a verb. Let's have some examples:
first: The boy likes the watch. [Boy=Subject, Likes=Verb, and Watch=Object]
With modifier of subject:
The boy who works in the library likes the watch. [Bold part is modifier of the boy]
With modifier of Object:
The boy likes the watch that is digital and keeps proper time. [Bold part is modifier of object, "watch"]
Hope it helps.