题干

有下列说法:
①有一个角为60°的等腰三角形是等边三角形;   ②两条平行线之间的距离处处相等;
③三边长为145,9的三角形为直角三角形; ④长方体、直六棱柱、圆锥都是多面体。
⑤一边上的中线等于这边长的一半的三角形是直角三角形。其中正确的个数是(      )。

A:1个

B:2个

C:3个

D:4个

上一题 下一题 0.0难度 选择题 更新时间:2015-12-28 04:12:12

答案(点此获取答案解析)

C

同类题3

阅读理解

    The next time you go grocery shopping, try speaking to other customers. One summer day, I took a smile and a warm heart into a small store in Oregon and got far more than groceries.

    I love fresh produce(农产品) in the store, and not just for the amazing colors provided by summer's bounty (慷慨) or the chance to joy over new choices from other countries. It's also because I just love watching people pick their produce.

    The day I was there I found a sale on amazing cherry tomatoes—along with a woman in her late 70s. Despite the fact that we were strangers, we began to discuss apples. She noted a problem with the Pink Ladies. "They tasted like I was eating an unripe green apple from the tree," she said, twisting her face as if still tasting the sour apple.

    I wondered if this is something most of my generation can even remember doing. I surely do. I mentioned that I often could not resist the green yet tempting fruit swinging from an apple tree. This was the start for a series of discussions as we shopped-covering such topics as nutrition, new foods and the quality of produce.

    By this time a third woman had joined in our conversation. The three of us continued along, unexpected friends, chatting about family size and the troubles a mom might have serving healthful foods that please the whole family.

    Eventually we all went our separate ways, but in the dairy(奶制品) section I heard a small voice say, "I finally caught up with you." It was the first woman I'd talked to, extending a bag of apricots(杏) to me. "I don't know if your family will eat these," she added, "but they have a super deal on them."

    Again I was brought back to my childhood, when I also ate apricots straight from the tree. My mouth watered at the remembered flavor.

    The old lady didn't realize that she'd given me far more than produce. With that offering came a sense of community, a flashback to days when it was OK to talk to a stranger. She brought back memories of summer fruits right from the tree—and a feeling that somehow those apricots were a thank-you for sharing my time with her in a very unlikely place.