在空白处填入适当代码，实现将text2放置在text1正上方效果。
< RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context="{activityClass}"
        android:background="@drawable/background">
        < TextView
                android:id="@+id/text1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:background="@drawable/go" />
        < TextView
                android:id="@+id/text2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/help"
                [填空1]
                [填空2]
        /