best ending?

Which is the better ending to the sentences below? Where is the continuous aspect needed?
1 Careful of the wet grass a) it's rained. b)it's been raining.
2 I feel exhausted; a) i've run up and down stairs all morning. b)i've been running up and down stairs all morning.
3 Watch that mirror! a)you'll break it if u r not becareful! b)you'll be breaking it if you are not becareful!
4 Don't come in here; a)i've dropped a glass on the floor. b)i've been dropping a glass on the floor?

6 Can you call me a bit later?a)i'll hv my dinner at that time b)i'll be having my dinner at .that time.