2. It's been six years since we last saw each other, you know.
你知道,自从我们上次见面以来已过去6年了。
It is / has been+一段时间+since +过去式表示“自从……至今已经多久了”。since“自从……以来”,表示事情持续的起点。
①以过去的时间点为起点,持续到现在,用现在完成时;
②从比过去更早的时间持续到过去,用过去完成时;
③从过去持续到将来,用将来完成时。
It's three years since he left for Australia.
=Three years have passed since he left for Australia.
自从他去澳大利亚以来已三年了。
句型探究
It be+时间+conj.句型
①It is / has been+时间段+since+一般过去时(从句中的动作是非延续性的)，意为“自从……至今已经多久了”。
It is (has been) ten years since I joined the army.
我参军已经10年了。
②It is / has been+时间段+since+一般过去时(从句中的动作是延续性的)，意为“不做……至今已经多久了”。
It is ten years since I smoked.
=It is ten years since I stopped smoking.
我戒烟10年了。
③It will(won?t)be+时间段+before+一般现在时,意为“还要过……之后才……”。
It will be ten days before I return home.
要过10天我才能回家。
④It was+时间段+before+一般过去时,意为“过了……之后才……”。
It was ten years before he found his lost son.
过了10年他才找到了他失踪的儿子。
⑤It is / was +时间点+when+…,意为“做某事是在某个具体的时间” 。
It was noon when the accident happened.
事故发生时已是正午。

3. What's the climate like?
气候怎么样？
What is...like?意为“……怎么样？”这种句型主要用来问人或事物的特征。
What is the weather like in Taiyuan?
太原的天气怎么样？
询问某人或某事的状况、特点还可以使用下列句型:
What be +主语+like?
=How be +主语？
What do you think of...？
=How do you like / find…
What do/does+主语+look like?
某人长相怎么样？
What's your English teacher like?
你的英语老师人怎么样(或长得怎么样)？
How do you like the dish?
这菜怎么样？