elearn site

1. Throw a stone into water and it sinks. (if)
. 

2. They started playing football an hour ago. (been)
. 

3. I can meet you if you arrive before eleven.
So long . 

4. You can′t visit France unless you get a visa. (if)
. 

5. If it doesn′t rain, they will go for a picnic.
Unless .