759.Both ________ and _____ laughter do harm your health.
A.burst out crying;burst into
B.to burst out tears;to burst into
C.bursting into tears;bursting into
D.bursting into crying;bursting out
760.Although punctual himself,the professor was quit used ______ late for his lecture.
A.to have students
B.for students'being
C.for students to be
D.to students'being
759.答案是C;此题中动名词作主语，表示一般的现象。burst into tears=burst out crying。
760.答案是D;be/get used to doing sth.习惯干某事。其中to为介词；而be used to do sth.被用来干某事。
