在工业设备的各种无损探伤方法中,()有较大的探伤厚度范围,但要求有较光洁的金属表面。 发布时间:2020-12-14 05:37 │ 来源:www.tikuol.com 题型:单项选择题 问题: 在工业设备的各种无损探伤方法中,()有较大的探伤厚度范围,但要求有较光洁的金属表面。A.超声波探伤B.磁粉探伤C.荧光探伤D.着色探伤
题型:单项选择题 如图所示,几只鸟在树上“歌唱”,一个听觉良好的女孩在一间门窗紧闭的甲房间内,靠近单层玻璃她能听到室外鸟的“歌声”;她到另一门窗紧闭的乙房间内,靠近双层玻璃(双层玻璃的夹层内抽成真空),她却几乎听不到室外鸟的“歌声”。(1)运用所学的物理知识,解释为什么女孩在乙房间内几乎听不到室外鸟的“歌声”。(2)女孩在两个房间都能看见室外树外的鸟,而只能在甲房间听到室外鸟的“歌声”,这说明光的传播和声音的传播有什么不同? 查看答案
题型:单项选择题 根据上下文, 从方框中选出适当的单词,完成下列对话。nice, way, from, tell, too, about, where, wears, reading, classmate Wang Mei is looking for Kate everywhere. She meets Jim at the gate of the library. Wang Mei: Hi, Jim. Jim: Hi, Wang Mei. 1________ to see you. Wang Mei: Nice to see you, 2________. Do you know 3________ Kate is? Jim: Who is Kate? Wang Mei: The girl 4________ the US. She is our new 5________. She has blond hair and big eyes. Jim: Do you mean the girl in a red dress? Wang Mei: No, she always 6________ a green sweater and blue pants. The girl in a red dress is Lucy. Jim: Oh, I see. She is 7________ in the library now, I think. You can go and find her there. She often comes here. Wang Mei: Thanks, Jim. By the 8________, do you go to the school library now? Jim: Yes, I do. I want to read 9________ some Chinese history. Wang Mei: Then could you 10________ her I'm waiting here? Jim: OK, I will. 查看答案