手选带式输送机的带速不得超过0.2m/s，倾角不得大于12°。
参考答案：错
有三个连续的自然数，其中最小的能被15整除，中间的能被17整除，最大的能被19整除．写出符合条件的这样的三个自然数．
—Excuse me, sir. Is there a young man named Liu Guozheng living here?
—I'm sorry, madam. He lives here ______. He moved to another place last month. [ ]
A. once upon a time
B. no longer
C. at last
D. all the time
