_____from lightweight materials，the robots are about the size of a human arm or
smaller．
| A．To build | B．Being built | C．Having built | D．Built |
He is so strongly built that he looks _______ he could lift an elephant.
| A．if | B．as if | C．like | D．that |
I’ll let you know ____ he comes back.
| A．before | B．because |
| C．as soon as | D．although |
She will sing a song ____ she is asked.
| A．if | B．unless | C．for | D．since |
We will work ____ we are needed.
| A．whenever | B．because | C．since | D．wherever |
Read it aloud _____ the class can hear you.
| A．so that | B．if | C．when | D．although |