抛物线y＝x2＋2x＋3的对称轴是( )_刷题宝

题干

抛物线y＝x²＋2x＋3的对称轴是( )

A：直线x＝1

B：直线x＝－1

C：直线x＝－2

D：直线x＝2

上一题下一题 0.0难度选择题更新时间:2012-09-25 09:19:15

答案(点此获取答案解析）

B

同类题1

I have never seen the word ______ that way before.

同类题2

下列实验操作先后顺序错误的是( )

同类题3

生物体通过呼吸作用将二氧化碳释放到大气中，绿色植物又可以通过光合作用作用，不断消耗大气中的二氧化碳，从而构成大气中氧气和二氧化碳的循环。请完成下面碳-氧平衡公式：

①____；②____；③____；④____.

同类题4

实验室常利用以下装置完成气体制备及性质实验．请回答：

同类题5

Dear Grandma and Grandpa,

I miss you so much. Thank you for the new bike! I'm so excited! How did you know 1 is my favorite color?

When I first 2 the box under the Christmas tree, I didn't know what it was. I thought it was 3 small to hold a bike. Then when I opened it, I saw that the bike was in small pieces. That's 4 the box was small!

Dad and I put them 5 the next day. It was a lot of fun. 6 we finished, I got on the blue bike and 7 around the town. My old bike was too small for me. This one is just 8. It looks great, too! All 9 friends want one like this now. Dad said that I could take my 10 when we go to visit you in the spring. I can't wait.

Yours,

David

小学学科试题库

初中学科试题库

高中学科试题库