Lake Baikal is (the deepest/deeper) lake in the world.
I know (what/that) Murmansk is (in/on) the north.
Rose (tells/says) the airport is situated outside the city.
We came up to the old castle. The door opened and we heard, “(Come/Go) in.”
At the weekend we went (on/for) a boat trip.
(Which/Who) of you is Boris?

the deeepest (глубочайшее)

that (в английском говорят: I know that..., I said that...)

says (tells - это скорее рассказывает, в английском принято использовать She says, I say)

Come - come используем, когда идём к говорящему, go - когда от

Which, who здесь не используется, это правило

he must know some foreign languages. he  must work now over the new novel. now they must enjoy fine weather.