How to display the result of two diffrent activities in the same xml view

Question

I'm trying to combine two listviews in the same view(main.xml),I'm trying to follow here,however the result of only one activity is always displayed in my case.

Here is my main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:weightSum="2" >

<LinearLayout
    android:id="@+id/linearLayout1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:orientation="vertical" >

    <ListView
        android:id="@android:id/list"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent" />
</LinearLayout>

<LinearLayout
    android:id="@+id/linearLayout1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/list1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1" />

    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Clear Cache" />
</LinearLayout>