用英语写出下列算式。 |
1. 15 + 5 = 20 _________________________________________________________ 2. 7 + 6 = 13 _________________________________________________________ 3. 11 + 7 = 18 _________________________________________________________ 4. 6 + 9 =? _________________________________________________________ 5. 17 + 3 =? _________________________________________________________ |