[lemma=must] [lemma=maintain] [word=a] □
[lemma=must] [lemma=maintain] [word=a] [□]
[lemma=must] [lemma=maintain] [word=a] []
Seedlings can only develop in full or nearly full sunlight ; trees must maintain a dominant or codominant canopy position to long survive . In addition , the operator must maintain a high quality of service ( QoS ) to ensure that . Since all operations that create a new lease also renew existing leases , the server must maintain a common lease expiration time for all valid leases for a given client . Hence , clinicians must maintain a high index of suspicion for cryptococcal disease , particularly in the setting of new onset of headache . They also must maintain a site-specific , written safety and health program based on OSHA guidelines and must train employees on hazards specific to their jobs . It must maintain a rigorous focus and the discipline needed to implement the vision .