You will want to right-click the previous measure and go to "Measure #." Choose the "Link to Next" option. You may need to go into Score>Full Score Options>Layout and change the notation size. You might also want to take a look at the layout handles by going to View>Show Layout Handles. Once you do this, you can use your mouse pointer to click and drag to adjust the horizontal spacing of measures to allow your linked measures to be in the same system.