Don't drop maths. I think maths is very important.

1. A.
   stop to learn
2. B.
   stop learning
3. C.
   fall
4. D.
   fall off

We often just drop ______ our friends’homes．

A．off　　B．in　　C．on D．by

Everyone should save every drop of water. Remember to _______the tap after you finish washing.

A. turn off                                                  B. turn down                                        C. turn on

Everyone should save every drop of water. Remember to _______the tap after you finish washing.

A．turn off                      B．turn down                            C．turn on