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【判断题】
成批生产时常采用模型锻造、机器造型铸造等方式生产毛坯A.
正确
B.
错误
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【简答题】在宽度为a=0.60mm的狭缝后放置一焦距f=40cm的会聚透镜，若以单色平行光垂直照射狭缝，则在置于透镜主焦平面处的屏幕上x=1.4mm处的P点看到衍射明条纹，求 (1)入射光的波长以及P点衍射条纹的级数； (2)在该衍射条件下，缝面可分成的半波带数； (3)中央明条纹的宽度以及第二级明纹对应的衍射角。
【简答题】利用波长为λ=0.59μm的平行单色光照射光栅，已知光栅上每毫米宽度内刻500条狭缝，透光狭缝宽度a=1×10 -3 mm．试求：
【单选题】PartI Vocabulary & Structure ( 25 points, 1 point for each item) Se c tion A Directions: There are 15 incomplete statements here. Complete each statement by choosing the appropriate answer from the 4 ...
A.
out, for
B.
off ,to
C.
out, in
D.
away, on
【单选题】下列有关准直器的描述，错误的是
A.
准直器狭缝宽度决定线束宽度
B.
准直器狭缝宽度决定扫描层厚
C.
准直器窗口呈狭缝状态
D.
准直器狭缝宽度决定扫描层距
E.
准直器位于X线窗口前端
【单选题】Choose the best item to complete each of the following sentences. 7. He always ______ the latest fashions.
A.
commented
B.
appeared
C.
followed
D.
attempted
【单选题】单色光的纯度可用仪器的狭缝宽度调节,宽度增加将会使( )
A.
单色光的纯度变差，测定灵敏度下降
B.
单色光的纯度变好，测定灵敏度下降
C.
单色光的纯度变差，测定灵敏度提高
D.
单色光的纯度变好，测定灵敏度提高
【单选题】Choose the best item to complete each of the following sentences. 1、 There’s no supermarket in the _____ area.
A.
immediate
B.
temporary
C.
recent
D.
brief
【单选题】Choose the best item to complete each of the following sentences. 4. Wearing long skirts has become very ______ recently.
A.
frequent
B.
popular
C.
famous
D.
average
【单选题】Choose the best item to complete each of the following sentence. 6.This sentence doesn't make any______.
A.
benefit
B.
sense
C.
help
D.
meaning
相关题目：
【单选题】下列有关准直器的描述，错误的是
A.
准直器狭缝宽度决定线束宽度
B.
准直器狭缝宽度决定扫描层厚
C.
准直器窗口呈狭缝状态
D.
准直器狭缝宽度决定扫描层距
E.
准直器位于X线窗口前端