title: android activity does not scroll down
body: <p>I m using android studio 1.0.... In design ,my screen is get filled and when it runs it needs to scroll down but its not ... I tried previous answers an add scroll view in layout but there is error ( Scroll view can host only one child) <code>enter code here</code></p>
  
  <p></p>
  
  <pre><code>&lt;ScrollView
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:orientation="vertical"
      android:id="@+id/ScrollView"&gt;
  
  
  &lt;TextView
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceLarge"
      android:text="INTRODUCTION:"
      android:id="@+id/heading1"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:textAlignment="center"
      android:phoneNumber="false"
      android:textStyle="bold" /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:text="@string/Introduction"
      android:id="@+id/textView2"
      android:layout_below="@+id/heading1"
      android:layout_alignParentLeft="true"
      android:layout_alignParentStart="true"
      android:layout_marginLeft="10dp"
      android:layout_marginStart="10dp" /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceLarge"
      android:text="HYDROCARBON:"
      android:id="@+id/textView3"
      android:layout_below="@+id/textView2"
      android:layout_alignParentLeft="true"
      android:layout_alignParentStart="true"
      android:textStyle="bold" /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:text="@string/hydrocarbon"
      android:id="@+id/textView4"
      android:layout_below="@+id/textView3"
      android:layout_alignLeft="@+id/textView2"
      android:layout_alignStart="@+id/textView2" /&gt;
  
  &lt;ImageView
      android:layout_width="150dp"
      android:layout_height="150dp"
      android:id="@+id/imageView"
      android:layout_below="@+id/textView4"
      android:layout_centerHorizontal="true"
      android:src="@drawable/ethane"
      /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceLarge"
      android:text="TYPES OF HYDROCARBON:"
      android:id="@+id/textView5"
      android:layout_below="@+id/imageView"
      android:layout_alignParentLeft="true"
      android:layout_alignParentStart="true"
      android:textStyle="bold" /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:text="@string/types"
      android:id="@+id/textView6"
      android:layout_below="@+id/textView5"
      android:layout_alignLeft="@+id/textView4"
      android:layout_alignStart="@+id/textView4" /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:text="Alkane"
      android:id="@+id/textView7"
      android:layout_below="@+id/textView6"
      android:layout_alignLeft="@+id/textView6"
      android:layout_alignStart="@+id/textView6" /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:text="Alkene"
      android:id="@+id/textView8"
      android:layout_below="@+id/textView7"
      android:layout_alignLeft="@+id/textView7"
      android:layout_alignStart="@+id/textView7" /&gt;
  
  &lt;TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:text="Alkyne"
      android:id="@+id/textView9"
      android:layout_below="@+id/textView8"
      android:layout_alignLeft="@+id/textView8"
      android:layout_alignStart="@+id/textView8" /&gt;
  
  &lt;Button
      style="?android:attr/buttonStyleSmall"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="BACK"
      android:id="@+id/button2"
      android:onClick="mainPage"
      android:layout_below="@+id/textView9"
      android:layout_alignRight="@+id/textView8"
      android:layout_alignEnd="@+id/textView8" /&gt;
  </code></pre>
  
  <p></p>
  
  <p></p>