$\text{⇒ Answer:}$

$\text{Bài tâp 1:}$

$\text{a) the weather is rather cold.}$

$\text{b) so.}$

$\text{c) because.}$

$\text{Bài tập 2:}$

$\text{a) I can't go out because it's raining.}$

$\text{b) There was fog, so their flight was delayed.}$

$\text{c) I could't do this exercise so I asked Tom for help.}$

$\text{Cho anh xin câu trả lời hay nhất nhé, please ~}$

because the weather is very cold

so i got lost

because 

i can't go out because the weather is raining

there were fog so their flight was bebđyed

i couldn't do this exergese so i asked tom for hep