A．Some tissues are more vulnerable to cancer.
B．Most types of cancers have been caused by unhealthy lifestyle.
C．Some of the cancers have no specific causes.
D．Smoking is a major risk factor for cancer.

A．Other types of diseases are closely linked to people's habits.
B．Healthy lifestyle can surely lower the risk of getting certain types of cancers.
C．People should make wise choices of everything.
D．There is scientific evidence of the function of healthy lifestyle.

A．Early detection should be attached much importance to.
B．It's unrealistic to prevent people from cancer.
C．More resources should be put in the treatment of cancer.
D．All types of cancers can be cured at their early stages.