比x的3倍少4的数是______,9除以2的商与7的和是______.
(1)x×3-4=3x-4;
(2)9÷2+7,
=4.5+7,
=11.5.
故答案为:3x-4,11.5.
Look at the photo. The two girls have big blue eyes and long brown hair. They are both ten years old. They are in the same class. The one in a yellow skirt is Lily. The other (另一个) in an orange skirt is Lucy. Their dad is Mr. White. He is in a brown coat. Their mom is Mrs White. She is in a black dress. Who is that boy in a blue cap? He is Lucy and Lily’s brother(哥哥)Bob. He is a high school student. Look! Lucy and Lily are in a black car.
根据短文内容,选择最佳答案。
小题1: Lucy and Lily are ________ years old.
A. 8 B. 9 C. 10
小题2:Lucy and Lily’s hair is ____________.
A. long and brown B. short and brown C. long and blond
小题3: Bob wears _________.
A. black shoes B. a blue cap C. a brown coat
小题4:Mr. White’s car is ________.
A. black B. blue C. green
小题5:Which is TRUE(哪一项是正确的?)
A. Lucy and Lily have two brothers.
B. The girl in an orange skirt is Lily.
C. Mrs. White’s dress is black.
设备检修是,零部件清洗作业应遵守哪些原则?