I / have / toothache / so / I / have to / see / dentist.

A. I have a toothache so I have to see dentist.

B. I have toothache so I have to see dentist.

C. I have a toothache so I have to see the dentist.

D. I have toothaches so I have to see the dentists.

Đạo hàm của hàm số  y = x 2 − 3 x + 2 3 là

A. 1 3 2 x − 3 x 2 − 3 x + 2 3 − 1

B. 3 2 x − 3 x 2 − 3 x + 2 3 + 1

C. 1 3 2 x − 3 x 2 − 3 x + 2 1 3

D. 3 2 x − 3 x 2 − 3 x + 2 3 − 1

Supply the correct form of the verbs in the blanket.

He (wash) ___________ his car once a month.