问题
选择题
下列各运算正确的是（ ）
A．m2+m3=m5
B．m2•m3=m5
C．（m2）3=m5
D．（m2）3=m8
答案
A、m2+m3≠m5，所以A选项错误；
B、a2•a3=a2+3=m5，所以B选项正确；
C、（a2）3=a6，所以C选项错误；
D、（a2）3=a6，所以D选项错误．
故选B．
搜题请搜索小程序“爱下问搜题”
下列各运算正确的是（ ）
A．m2+m3=m5
B．m2•m3=m5
C．（m2）3=m5
D．（m2）3=m8
A、m2+m3≠m5，所以A选项错误；
B、a2•a3=a2+3=m5，所以B选项正确；
C、（a2）3=a6，所以C选项错误；
D、（a2）3=a6，所以D选项错误．
故选B．
| Cloze test. 完形填空。 |
| Ann is l English girl. She is fourteen. She is a 2 student. Her teacher is Miss White. Ann is helping her to put 3 books and ruler on the desk. They have a new 4 . You can 5 40 desks and chairs in it. A blackboard, a clock and a map are 6 the wall. There are some pens on the desks. The red 7 is Ann's. Others (其他的) are Kate's. Kate is Ann's 8 friend. She isn't 9 here today. She is ill. Look at the clock. It's about four o'clock. It's time 10 and play games. |
| ( ) l. A. a ( ) 2. A. middle school ( ) 3. A. my ( ) 4. A. room ( ) 5. A. look ( ) 6. A. on ( ) 7. A. pens ( ) 8. A. fine ( ) 9. A. / ( ) 10. A. come | B. an B. Middle School B. your B. class B. look at B. in B. pencil B. good B. at B. go | C. the C. middle school's C. his C. grade C. see C. at C. one C. nice C. on C. to come | D. / D. Middle School's D. her D. classroom D. see at D. to D. ones D. right D. of D. to go |