—It’s difficult to tell this picture from that one.—Yes.The differences between the pictures are very________.

John has tried many ways to solve the physics problems, but ________ works.

 In class the teacher ________ the finance project in simple but vivid language to make it easier for us to understand.

When my grandfather retired(退休) at the age of 60, he took a sea ________ around the world, which had been his dream since his childhood.

Emails are efficient and convenient, but the best way to __________ a message is still to talk it out in person.