Раскройте скобки, обращая внимание на форму времени глагола-сказуемого. 1). We (to come across) a very interesting article in the magazine. Let us discuss it together.
2). Is everybody here?- No Peter (not to come) yet​

Щас.

1. We came across a very interesting article in the magazine. Let us discuss it together.

2.Is everybody here? - No, Peter hadn't come yet.

1). We came across a very interesting article in the magazine. Let's discuss this together.

2). All here? - No, Peter hasn't come yet