Smart phones are helpful. However，some people use them only for mobile games. __________！
A.What a surprise B.What surprise C.What a waste D.What waste
Lin Tao is so good at German that I'm wondering __________.
A.if he has been to Germany before B.how long has he been to Germany
C.if he has gone to Germany before D.how long has he gone to Germany
Mr. Jobs together with others started the company Apple Inc. in 1976 and made it a technology__________.
A.inventor B.engineer C.pioneer D.fighter
When you see your right moment，you __________let it pass you by.
A.need B.needn't C.must D.mustn't
Boys and girls，you should be __________to avoid making mistakes while taking the exam.
A.too careful B.careful enough C.too careless D.careless enough
There's no snake that will habitually（习惯性地）attack humans__________ it is in danger.
A.unless B.if C.though D.since
