When did you get to Shanghai?

When did you____ ____ Shanghai?

我国历史上第一次大规模农民起义——大泽乡起义的领导者是（   ）
①陈胜②项羽③吴广④刘邦

无级变速是在变速范围内任意连续地变换速度，性能优于传统的挡位变速器，很多种高档汽车都应用了无级变速．如图所示是截锥式无级变速模型示意图，两个锥轮之间有一个滚轮，主动轮、滚轮、从动轮之间靠着彼此之间的摩擦力带动．当位于主动轮和从动轮之间的滚轮从左向右移动时，从动轮降低转速；滚轮从右向左移动时，从动轮转速增加，当滚轮位于主动轮直径D₁、从动轮直径D₂的位置时，主动轮转速n₁、从动轮转速n₂的关系是(　　)

阅读下面短文。从短文后所给的A、B、C三个选项中选出最佳选项。

    A man stopped at a gas station and bought a soft drink. He stood by his car to 1 and he watched a couple of men 2 along the roadside.

    One man would dig a hole two or three feet 3 and then move on. 4man came along behind to fill in the hole. While one was digging a new hole, the other was about 25 feet behind 5 in the old hole.

    The man with a soft drink was confused. "I can't stand this," said the man walking toward the men. "Stop it," he said to t e men. "Can you tell me what's 6 here?"

    "Well, we work for the county government," one of the men said.

    "But one of you is digging a hole and the other is filling 7up. You're not accomplishing anything. Aren't you 8 the county's money?"

    "You don't understand," one of the men said.

    "Normally (通常地) there are 9 of us: I Rodney and Mike. I dig the hole Rodney sticks in the tree and Mike here puts earth 10."

    "Yeah," said Mike. "Today Rodney is sick. But that doesn't mean we can't work, does it?"

从食品安全角度考虑，正确的做法是（     ）