根据短文内容，判断正误。

    People in New Zealand have a very special way of greeting(问候) people. It's called Hongi(碰鼻礼).

    When people meet, they always greet each other by pressing one's nose against another's nose. When a visitor is greeted in this way, people there won't see the person as a visitor any more, but one of the people of the land. Of course, during the visitor's stay, he has to share all the duties(职责).

    At meetings or important ceremonies(典礼) people always greet in this way. And it's just like the handshake in our country.

图甲是“研究平抛物体的运动”的实验装置图．

①实验前应对实验装置反复调节，直到斜槽末端切线____，每次让小球从同一位置由静止释放，是为了每次平抛____．

②图乙是正确实验取得的数据，其中O为抛出点，则此小球作平抛运动的初速度为____ m/s．（g取9.8m/s²）

③在另一次实验中将白纸换成方格纸，每小格的边长L=0.8cm，通过实验，记录了小球在运动途中的三个位置，如图丙所示，则该小球做平抛运动的初速度为____ m/s；B点的竖直分速度为____ m/s．（g取10m/s²）

“螳螂捕蝉，黄雀在后”这一食物链可以准确的表述为（　　）