E. Choose the correct item.
25 Ulan joined the clean-up day because/for he cares about the environment.
26 It was solsuch cold yesterday that the water pipes in the house froze.
27 As/For they were working, they couldn't join us for dinner.
28 She has such/so a lot of money that she can give lots to charity.
29 Since/So they were late for class, they had to stay back at school.
30 The sea has such/so much pollution that it's not safe to swim in it.