The back garden of our house contains a lawn ，____very pleasant to sit on in summer.
A、whichisA
「句意」我家的后花园有一片草坪，夏天坐在上面会令你心旷神怡。
「难点」which引出非限制性定语从句，在句中作主语，且和siton构成动宾关系。类似的句子有：Thisroomiscomfortabletolivein这句中livein和thisroom构成动宾关系。
Modern____perhapscausesmoreproblemsthanitsolves.
Ifasubstanceisdissolvedinwaterorheated，itmay（）agas.
_____enough time and money, the researchers would have been able to discover more in this field.
Indeed, it is arguable that body shattering is the very point of football, as killing and maiming___.
_____nocauseforalarm,theoldmanwentbacktohisroom.
