I’m all ____ sea and I’ve no idea how to fix my pencil box.
| A．in | B．on | C．at | D．off |
We built this factory ______ top speed and minimum(最少的) cost.
| A．in | B．at | C．with | D．on |
There is a big and beautiful lake ______ the foot of the hill.
| A．at | B．in | C．with | D．on |
We go _____ duty at 8 a.m.
| A．on | B．in | C．at | D．for |
Li and I arrived ______ Heishan country safe and sound, all is well. Don’t be worry.
| A．in | B．on | C．/ | D．at |