a) Transport system provides (Present Simple Active Voice) the public with important services.
b) The international economy has experienced ( Present Perfect Active Voice) a basic change lately.
c) After economic integration had grown ( Past Perfect Active Voice),more and more nations became( Past Simple Active Voice) economically powerful.
d) The population of most developing nations is growing ( Present Progressive Active Voice) rapidly.
e) There will be ( Future Simple Active Voice) a great rise in the demand for coffee.