Dear Abby，

    I'm a helpless mother. My son Tom is 15 years old. I find that the older he grows, the less we talk. I feel very sad and I really need help.

    My first problem is about his hobbies. He spends almost all his spare time on computer games. When he gets home, he always turns on the computer and closes the door. I'm getting worriedabout him, especially when his English teacher tells me he always gets low marks in the English exams.

    Second, he likes newtechnology，but I don't have enough money and I can't afford all the things he wants.

    Recently, I've foundthat he is always alone. I've never seen him talking to his friends on the phone or going out with anyone on weekends. That is the last problem I have.

    What should I do to help him? Pleasegive me some advice.

A helpless mother

若有两个电阻R1、R2(R2＞R1)，设串联后的总电阻为R串，并联后的总电阻为R并，那么一定有（）

步骤1：在OB上任取一点M，以点M为圆心，MO长为半径画半圆，分别交OA、OB于点P、Q；

步骤2：过点M作PQ的垂线交 $\widehat{PQ}$ 于点C；

步骤3：画射线OC．

则下列判断：① $\widehat{PC}$ = $\widehat{CQ}$ ；②MC∥OA；③OP=PQ；④OC平分∠AOB，其中正确的个数为（   ）

清真寺是哪个宗教的景观（　　）

________ tourists like to climb the Great Wall, and ________ them is increasing now.