It is strongly recommended that the machine_____________ every year.
| A．are checked | B．should check | C．checked | D．be checked |
I felt surprised that anyone of his intelligence such an easy test.
| A．might have failed | B．could have failed |
| C．should have failed | D．must have failed |
I was feeling left out in the new school ________Alice, an easygoing girl from Canada, came to stay with me.
| A．if | B．once | C．when | D．unless |
According to its website, each tattoo lasts around seven days, ________ it isn't scrubbed or picked at.
| A．having provided | B．provided that |
| C．providing that | D．being provided |
—Why didn’t you finish the task? —I didn’t think it is ________ the effort.
| A．worthwhile | B．deserving |
| C．valuable | D．worth |
______ is important now for the Chinese economy is to adapt to the new normal.
| A．What | B．That | C．It | D．As |