Which of the following countries has the smallest amount of known crude oil reserves?

Which barrier to economic development is shown in the following examples?

The us and canadian governments are doing all of the following to combat environmental problems except a. encouraging the use of public transportation b. enacting clean water policies c. requiring emissions testing d. limiting animal populations in some regions

Will give brainliest asaapppppppppppp plz im in a major hurry to finish which of these pairs of objects exerts the greatest gravitational force on each other? object 1 and object 3 object 4 and object 3 object 1 and object 4 object 4 and object 2