凡两构件通过点或线接触而构成的运动副统称为()。
A.低副
B.高副
C.转动副
D.移动副
参考答案:B
用所给单词的适当形式填空。
1. My mother is used to (go) shopping on Sundays.
2. They go out of their way to make me ____ (feel) at home.
3.I find it difficult (understand) everything.
4. His bike is (difference) from mine.
5. There is no reason___ (come) to school late today.
慢性胃炎患者可选用的治疗膳食是()。
A.少渣半流食
B.低盐膳食
C.高纤维膳食
D.高支链氨基酸膳食
E.低铜膳食